@Neurotic:
Since the healing chain is a ranged touch attack, if you target Camburn, then Akos would be firing into melee and the captain has cover from the tree and the numerous foes in between him and Akos. That would make the captain's touch AC 23 and your ranged touch attack 23-4 = 19 (Knowledge Devotion does apply). So, that would be a miss.
However, if you could target Zenpher first (touch AC 16), you wouldn't have to worry about cover. Akos would still be firing into melee. Knowledge Devotion would still apply, I think (humanoids, right?). So, again, 19, which hits.
Chaining it to Captain Camburn might be a hit or a miss depending on whether or not 'firing into melee' applies to the chaining part. Cover probably doesn't apply since it is an arc (

). If firing into melee does apply for the arc, then it would be a miss (20-4 = 16). If it doesn't, then it would be a hit (20). I'm going to say the arc would hit Camburn.
Akos would know that his chance of hitting Captain Camburn
first is very low with the tree in the way and the # of Loyalists and mercenaries in between him and the captain.
The window is half-open, and the open door is blocking part of the window. Plus, I don't think the chain would arc back from Camburn, through the window, and then turn into the corner and hit Tuck... even with Akos guiding it. That seems very unlikely, even in a world of magic.
However, since I let JustinCase have Tuck throw a vial of acid through that window at one of the Loyalists (early in the combat), I'll allow the chain to arc from Zenpher through the window and hit Tuck. The door should be in the way, but if it was, then Tuck wouldn't have been able to throw the acid at the soldier in the first place.
Zenpher could get 18 and either Camburn or Tuck gets 9. Or you could target Tuck first and then have it arc to Zenpher (or Vinny).
Akos can't see Tim.