One of the playstyle considerations I'm struggling with is a perceived lack of interesting tactical impact on the decision to use a healing power. The leader classes as a whole have very few uses for their minors outside healing so there is typically no opportunity cost to be weighed in deciding whether or not to use the heal power.
Couldn't disagree more. The shaman in my game is so minor action challenged, he will occasionally give up a standard action because he needs to do 3 minor actions, or a move action two minors. The tactical impact is most certainly there. My warlord would assess the situation and sometimes used his minor to buff someone to take out an enemy rather than heal someone in need. Clerics who need to sustain dailies, and move and heal often have to give up a standard action. I could go on...
Now a follow up question. Would it have any bearing on your opinion if the various Word powers were at-will standard actions rather than Encounter powers?
It would be a different mechanic for low levels, and I still wouldn't want to "play the cleric". That's basically what wands were in 3.x. And by high paragon, the healing *seems* to be at-will already (looking at you Mr Warlord with 4 heals per encounter). So I don't think my opinion would change.