Hopeling

Because it's the second-best-DPA attack in the set, and because without it you don't have anything even resembling an ST chain. A fast power with 100% chance of knockdown is nice utility, too.

Defensive Sweep's def buff isn't ideal for /Inv since it gives mostly positional defense, and it does very poor damage, especially for something you'd have to use every few seconds to keep the buff up. Crushing Blow is important for a pure single-target chain, as Reppu has said, although situations calling for pure single-target are not terribly common (basically just AV fights). Of course, you have to take one of the two, so decide which will be more useful to you.

No, the cap is 775% if you're including the base 100%. It's 675% after you subtract that away. As in, your damage stat in combat attributes turns blue at 675 (although the slotting in your powers means you'll actually be ~95% past the damage cap by then). SonicRemedy had it right.

So yeah, you need Fulcrum Shift or a lot of red inspirations to hit the damage cap on a brute, so that part is not really an issue.
The stacking damage buff in Core will be equally beneficial to all of your powers, but you do have to build and maintain stacks. The math for doublehit is kind of weird, but basically it strongly favors long-recharge single-target attacks, and... disfavors(?) large AoEs and short-recharge attacks. You don't have to build stacks, though, it does all the bonus damage up front.

"You and thirty-nine of your closest friends can enjoy this instance for six or more hours at a time!" No joke, a friend of mine could literally do the Blackrock Mountain corpse run with his eyes closed.

CoH's long history and unusually high retention rate also means we have a lot of veterans, which is also a boon to forming and leading teams. Odds are that, if i put together a Numina, at the appropriate point I can just say "perez, atlas, steel, kings, skyway" and everyone will know what that means.

Because it's not currently in the market, and premium accounts do not have access to it without purchase (like First Ward).

That sounds like a pretty direct response to people who want it to be always on. I'm not sure how he could respond so directly to such posters without listening to them. After listening to and considering a request, the answer can still be a flat "no". That's not failing to listen.

...and when it was stated point-blank that Hybrid would have a cooldown, and players kept asking for it to not have one... well, that's not the devs that are refusing to listen.

Right... that was my point.

An always-on toggle was not within the scope of what they were trying to do, which was to make you actively choose when to use the power, rather than just leave it on all the time, as they said from the very start of the beta.

I think the solution should have been unlimited free ponies for everyone. However, the devs have a concept of what they want Hybrid to do, and that concept has no room for unlimited free ponies, so my opinion on the matter is rather irrelevant.

Right, exactly.

The "I would rather deal with the end cost and run it all the time" approach is WHY it was changed. It was changed to prevent people from doing that, because it's intended to not be run all the time. And it would also disproportionately favor sets/builds with strong endurance tools, while being disproportionately useless for sets/builds that already struggle with endurance. An always-on toggle with a cost was opposite the design goal, and in a way that drastically favored some builds over others. An always-on toggle with a lower cost but lesser effects was never even on the table,

It was intended from the beginning to be an "actively choose when to use" power, not a "toggle on and leave on forever" power, and was explicitly explained as such, as evidenced by the feedback questions Freitag used to start the feedback thread. The initial design, with the endurance cost, failed to accomplish that intention, as multiple players pointed out, and so it was changed.
Hybrid had a specific design goal; players saw a new Incarnate slot and projected all their hopes and wishes onto it, regardless of whether they met the design goal or were at all balanced. A LOT of player feedback and input went into the Hybrid slot; all four trees are dramatically different than when they first went up on beta.

Everything in the game is done on dev terms. That's not apologism, that is a basic fact.

I wouldn't exactly be surprised by such a bug, but it's a bit unrealistically pessimistic to predict that the whole mechanic fundamentally fails to work before anyone has even tested it.

Us VIPs, yes, but they are not in the market yet. Nor is Night Ward.

Right, your test definitely shows that Radial wins for your attack chain, but the question is whether that result can be extrapolated to all powersets. Since TW is unusual in ways that directly affect how much it benefits from doublehit, I'm not at all convinced it is representative. A Gloom-less SS brute might not do so well with doublehit, for example, since only two attacks in the set are really slow, and one of them (Foot Stomp) has an aoefactor of ~3 that penalizes its doublehit effectiveness twice (granted, the brute's lower damage scale might still make Radial more attractive than Core). A Dual Pistols character might also gain less benefit, since HoB is such a key power, but doublehit caps recharge at 20 seconds for its damage calculation (and caps it before applying the aoefactor penalty, which is quite large - 4.75 - for HoB).
Altogether, doublehit damage on HoB should be, according to the City of Data formula,
(0.8 * 20 + 1.8) * 2 * 107.09 / 10 / 4.75 * 0.4
= 32.1, regardless of AT.
Whereas +75% damage from Core adds ~130 to HoB with Incendiary Ammo for a Corruptor, more than four times as much. A Blaster would gain a yet larger benefit.

For Titan Weapons, yeah, Radial definitely wins. For other sets with mostly long-recharge attacks, too. But that's not every set, and double-dipping on the aoefactor penalty might mean Radial generally loses for AoE powers. Needs more testing.

According to the formula UberGuy posted, animation time doesn't affect doublehit damage at all, only recharge time does. It would affect proc chance, since PPM procs are based on total cycle time (recharge + activation), but not by much, and attacks with recharge >=10s (which is 4/5 of Reppu's attack chain) have a 100% proc chance anyway (and the 5th attack would have a 92% proc chance even if the Momentum speed were used).

The i24 PPM changes will make animation time matter more, but not by much. Animation time is a relatively small part of cycle time.

So, in short... since it has barely any effect at all, it does seem pretty likely they will let it stand. What might change, though, is letting doublehit double-dip on recharge, disproportionately favoring slower power sets like TW.