I think Scoundrel healing suffers from a few problems that I'd like to see addressed. Right now I believe the class is viable in all of the existing content, but it lacks flexibility. The major problems that I see right now are:
(1) Weak AOE healing.
(2) Wasted Upper Hand procs from our HoTs (since we're often in the cast of Underworld Medicine).
(3) Mostly useless Kolto Infusion heal.
I have the following ideas for how to improve the class:
(1) Weak AOE healing.
We know that front-loading of Recuperative Nanotech is planned, and that should help a bit. I would like to see two additional improvements to this ability:
(a) Make Recuperative Nanotech "smart." When cast on a target, instead of picking the three people closest to that target as the additional targets, instead pick the three people within range that have the lowest health. This makes it function more like a shaman Chain Heal and there is less likelihood of overheal.
(b) Have Recuperative Nanotech also refresh Slow-release Medpac stacks on those targets. It doesn't have to apply a second stack or anything.... just refresh any existing HoTs.
(2) Wasted Upper Hand procs from our HoTs.
I would like to see Accomplished Sawbones (the talent deep in the healing talent tree) allow us to gain one additional stack of Upper Hand, for a total of 3 stacks of Upper Hand. This would have the benefit of reducing the likelihood that we would waste procs of Upper Hand. It would make HoT procs more useful and help a bit with burst healing capability, since you'd have more opportunities to do two back to back EMPs compared to now.
(3) Mostly useless Kolto Infusion heal.
My suggestion here would be to change Kolto Infusion so that it consumes all stacks of UH but one. Combined with my suggestion in (2), this would enable you to get to 3 stacks of UH and then blow Kolto Infusion for more than 2x the healing of a single EMP. Note that low level scoundrels would be completely unaffected by this change, and it would really only come into play as you closed in on the higher levels.
I think you should also consider giving Scoundrels a couple of long cooldown tools as well. I'll just list a bunch of examples. I don't think we need all of these, but one or two would be nice.
(1) Ability to gain full UH stacks. Similar to how a paladin can pop Divine Plea to gain 3 Holy Power, you could envision giving us a 2 or 3 min CD to instantly jump to 3 Upper Hand.
(2) The ability to consume our HoTs and do all the remaining healing on a target instantly. Would be very interesting if it worked on both RN and SRMP HoTs. A 1 min CD or so would be reasonable here.
(3) A straight up plus healing ability, e.g., something like Avenging Wrath in WoW for paladins, you could imagine a 2 or 3 min CD that just gave us +20% healing for 10-20 seconds.
(4) Lay on Hands. Maybe give us a 10 min CD to fully heal a player.
(5) Hand of Sacrifice. Maybe allow us to put a damage reduction on a player that redirects to our Defensive Screen somehow (similar to the paladin bubble+sac combo).
(6) Tranquility. Consider a long cooldown massive AOE heal (10 min).
There are so many creative options here to give us a bit of utility. My own preference would be to for a Lay on Hands ability, since it addresses some of our weaknesses. Turning Defensive Screen into a true paladin bubble would be interesting too, e.g., give it a guaranteed minimum immunity time (and reduce damage done massively while it's up so it can't be abused).
