Seldom

It's the untyped/unresistable damage. With phantom army's recharge as-is, they really need to make the decoys immune to it as they certainly aren't smart enough or controllable enough to pull them 'out of danger' easily.

The OP asked specifically about Fire based characters, and referenced a ranged fire dominator. Immobilizes are handy at times, but early on draw aggro far more often than a fire dominator would like. A 'young' fire/fire dominator has no healing, no soft control to stun/sleep/kb or such, and only one readily available control that actually stops damage. As such, when playing a ranged fire/fire dominator against enemies that will always out range you, I find holding off on immobilizes in favor of picking up the needed secondary attacks and maybe even the couple of powerpools you want to be better. Picking up immobilizes after flashfire (level 12) is just safer, even if you must deal with melee foes at times. If you fire cage a whole group before flashfires they all shoot at you at once, and you only have one power, (char) that can stop one of them from countering. It's safer to start out single-target based and have a smaller aggro footprint until you can handle more.

That may be different for a character with another toolset, but trust me: there's more danger a fire/fire dominator will be in using ring of fire/fire cages at levels 1&2 up through level 12 than if they opted for early powers that take down enemies or help with more direct utility, (hover to stay out of range, hasten to speed up attacks/the hold, stealth to stack with smoke to sneak, and so on) even if they lose the ability to lock a foe at range or lock a group out of LoS to minimize return fire.

Hehe. Dominators and corruptors are two entirely different animals. Corruptors will almost always have more AoE options than dominators, at least until you get to the ancillary pools. Corruptors start as medium damage, but hit high damage once foes start getting hurt. They, like defenders/controllers, can make that damage higher through buffs/debuffs in their secondary. Dominators start high damage, and if you go /fiery, only get higher. Their problem is a bit different: all their powers are high damage, but their attacks come late and they have fewer of them, splitting attacks with controls/utility powers.

Corruptors, especially if you go fire/thermal as your fire theme would suggest, positively shine on a team. Solo some secondaries lose utility, and except for /traps and /sonic, they lack a way to work around mez. So pack break frees, elsewise you will find yourself often rendered helpless by controls. Corruptors do decent damage, but since they have a higher % chance to double it with scourge based on low hp, they shine vs. hard targets. The larger hp pool of those mean they spend a longer time being hurt but not dead, which means more double damage.

Dominators work the same way whether on a team or solo. They control foes, then kill. Due to their high damage, you can just kill the stuff that will die in a couple hits, control that which won't. Dominators are as safe as you build/play them, and reward canny decisions...but if you aren't aware of foes and let them go uncontrolled, your low heath will dwindle quickly. Dominators rely on an active inherent power, domination, far ore than corruptors do for staying alive/reacting to circumstances. It fills endurance, grants near mez/knockback immunity, and boosts your own controls to the point that they last 50% longer and control bosses in one hit. This power can be accessed based on recharge and a bar that builds from using attacks/controls. (Attacks build it faster, and dominators build domination faster near allies) Because +recharge set bonuses/powers boost how fast it comes back, many will tell you that using +recharge IO sets will greatly increase many dominators' performance, depending on the primary. Hasten is also uniquely helpful.

If you are considering going fire/fire/fire on a dominator, I can tell you early on it's tough because dominators get their attacks slowly, and you should avoid immobilizes from the primary until later. Controllers like these early on because the do double damage and don't have attacks, but on dominators they do little damage, and simply tie down an enemy, essentially saying "Stay there and shoot at ME!" Later they can be handy, but only once you have more attacks/controls that halt return fire. Early on a fire/fire dominator plays like a weaker blaster with holds. Flashfire is your MAIN survival tool, and once you get it slotted well your true power starts to show. After you can stun an entire group, then you may consider the immobilize the hold them still. Hotfeet from Fire/ will give you lots of trouble and not much return on a ranged dominator, so it's a good way to skip extra aggro/endurance drain. (I love it, but I tend to play close) So your ST hold/AoE stun are the mainstays for openers, then you go nuts with your fire blasts. Then you get imps,blaze, and if you go with the fire APP, rain of fire/fireball, and you become a blaster than can at times stun/hold an entire group of bosses single-handedly, light them all on fire as your pets tear into them, blasting them to death as you cackle maniacally at how unfairly fun it is.

Confuse doesn't cause foes to generically "change sides." It causes them to target and attack any faction flagged as 'enemy' to players, and not target any entities flagged as 'ally.' So if they confuse a target, the target just attacks more of the player's foes.

As for the question at hand: I'm HIGHLY biased, my main character being a Mind/Psi dom since doms existed, but that'll tell you just how much mileage mind/psi doms can give you. Blasters got a slightly modified version of psi blast, which lost the extra range it had in the hands of defenders. Aside from that it's a decent set, and along with /mental can be pretty safe. Just know that it won't be anywhere near as safe as the Mind/Psi dom, as that has superior control, drain psyche, and mez protection. (The last gained via domination) If you are looking into investing IO's into the character, the dominator will benefit far more from that.

If done correctly, having a cross-server system would solve the problem of finding a pick-up team at the drop of a hat at the largest level. If the SG/VG problem as well as naming issues, and one could have unlimited transfers, you'd go from having access to one pool of players to being able to 'swap pools.' If you could access ALL servers, you are not just limited to one pool at time, but all at once. Unlimited transfers would be like this:

Player #1 starts on server A

• find things are slow
• Transfer to server B
• (a) find things more populous, or (b) find things are slow as well.
• If (b) is true, transfer to server C

This starts a new problem as well. Player #2 on server A

• they want to team, but things are even slower with player #1 gone.
• Transfer to server C, since it is the busiest populous at the moment.

A cross-server teaming mechanic could bypass hopping from server to server to try to form something or look around for a team. If it could allow a team to be formed regardless of server, then the busy work of looking around is bypassed and you don't run into the issue of making any single server become the grouping point, you let the system facilitate getting to the endpoint, and bypass much of the busy work.

I'm pretty darned sure that any cross-server system would use an opt-in crowd gathering system of the LFG tab, which means the devs get much fuller use from that system and allow for a much more direct means of recruitment. Example: it's 2 in the afternoon, Player #1 wants to form a BAF. only 10 50's are on, and half don't want a trial. Rather than telling the half that do want to to transfer to the next server for a larger group to coalesce, they all hit the LFG, and every player from every server who wants in gets dropped into the trial, stopping at the limit.
Yes, I know that brings up the issue of a blind invitation system, 'unblanced' teams, and all that stuff that people don't like about the LFG engine. But it does solve any pick up teaming complaints by taking an immediate account of all logged in and willing players at once, as soon as they join such a queue.

I'm a bit of a spaz in combat. Partly to line up cones, (even sands of Mu) partly to hit as many things with pbAoE's, partly to gain/lose aggro, partly to jump-cancel long animations, partly to just, well, move. Perhaps because I'm so used to the dominator playstyle (fire cones from outside combat, jump in the thick of things for AoE, fire blasts as jumping out to line up for the next cone) I just feel bored unless I'm giving chase or maneuvering to best effect.

*edit*
Jump canceling and midair animations actually allow you to bypass the limitations of a stationary animation and allow the character to be in a better position so you can immediately follow one power into the next, in situations where you would usually have to take time to move between attacks. as mobs jostle with each other in crowded environments, mid-combat movement allows you to keep as many in range for your next power. Standing around means you are at the mercy of fickle AI that may run outside an AoE, run away, or suddenly move to the wrong side of an obstacle, thus not getting hurt. This is of course more likely to happen on large teams or when set for large spawn sizes. It's actually best to position for your next power, not your current one.

*Cough*

It's true the melee powers don't work as reliably with archery if used together frequently, but boost range more than makes up for this. No archery power needs you to be close, so boost range greatly helps archery, more so than almost any other attacks set. The range can be so great that you get 2-3 extra attacks in as they try to close, often ending with them dead rather than hitting you. and once they get close, power thrust them back and fill them with pointy sticks.

As to the OP, I'll have to say EN/Fire is not the best. Energy gives some mitigation, but what it gives clashes with much of /fire. A friend who i convinced to play the game a while back had an Energy/Fire as his first and main character, he quit soon after getting it to 40. (This was back before IO's were available to ease some of the survival issues)

While /psi lacks and damage boosting abilities, it is hardly low damage. To be honest, it's medium damage. True, psychic meets with heavy resistances, but psy resistance tends to be "all or nothing." Psychic/machine, etc enemies are a real pain, but most other targets will take full damage. /Psi lack burst damage, but instead relies on a steady stream approach, and since it has two very good AoE abilities, it most certainly pulls ahead of more single target secondaries in most gameplay. /Psi is middle of the pack for damage, and moves up the ladder when considered against larger spawns.

As to why elec/psi isn't considered great? I can't say, but I would guess because it has indirect rather than direct strength. I can easily make entire mobs helpless because they cannot fight back a dominator, especially a perma-dom, but many would prefer brutes/scrappers/tanks that get continuously punched in the face and live. Control I find to be one of the most undervalued skills in CoH/V. Beyond this, sapping (-recovery+ -end) is very binary. With it, it's awesome. My kin/elec defender has made giant monsters damageless for over 10 minutes. But the instant that tick of end shows up again, the danger is back to full strength. As such, those who aren't staying on top of their sapping and let those ticks of blue show up get punched in the face, and don't feel awesome. In the end, anything that needs some strategy/effort to maintain its coolness but dies when you get sloppy? Not so popular.