Look at what your powers do and look at what can stack because offering more than what you can already do is better than offering a little bit of this and a little bit of that.
Here is the type of stuff you could add to become "flexible enough for most teams to not really need another controller or defender in the vicinity."
haste = more of what you got over time.
Flash Arrow + Manuevers can = 15% circa def which when you lower damage and dps through -rechg is not too bad at all and especially good for people of some sets. My SR running basic slots and toggles would be elusive.
Acid Arrow + Disruption Arrow + Assault = -Res and + Dam = what fight duration? Couple this with your own Oil Slick Arrow on top of what the team can do and its an enormous amount of carnage.
Acid Arrow + Oil Slick Arrow + Tactics "Wait" Acid Arrow and OSA together would have you at -50% def but they don't come together as regular as one would hope, but Tactics is always good for your own accuracy and perception as well as other peoples.
Vengeance = When the bleep hits the fan you could EMP arrow everything but I am sure the rest of the team and your endurance bar would appreciate this more.
Medicine Pool.
Stimulant okay for other defenders or controllers doing the Tank maging, you could be but sometimes its better or easier if they are "sometimes".
Aid Other - what if there is no one else that can defend or control except you? Topping up of healthpoints in between fights can result in less downtime (waiting for someone else to be confidently ready).
Aid Self - This was purely because of the size of my AoEs and the lack of aggro control other people are supposed to offer. This means that I have had at times no one to help me after the debuffs went in.
Resuscitate - Again downtime, people could use awakens or you could have them made but it only takes an endurance slot or 2, yes even TAs don't find the need to slot for rechg 
Later Conserve Power, either you've over spammed a power beyond its necessary use or done so after EMP or some of the slotting requires more end redux - with stamina.
Power Boost - I got this for my Vengeance, Aid Other and Controls.
Other powers like -
Stealth will allow you to get around the fact you can't add range to flash arrow slightly.
What I've not had a problem of playing without are:
Combat Jump - you resist Immobs and you have a small bonus to def.
Acrobatics - You resist holds and kb (Your supposed to be ranged and you do control so this can be v unnecessary)
Fight pool, TP and Presence - each to their own quirks I say.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
Hi Guys
As with a few other people/builds, Pool Powers are causing me some problems for my TA/A defender. Currently I have the Stamina set and Fly but am not sure what else to go for. I have dabbled with a couple but none felt right and so far I am down to my last Vet Respec having used one already and also messing up my first build lol
Golden-Phoenix - Lvl 50 Fire/Fire Tank
Oodja Nikabolokov - Lvl 50 SS/WP Brute
Baby-Phoenix - Lvl 50 Peacebringer
How much wood would a woodchuck chuck if a woodchuck could Chuck Norris?