I hit my nose when leaning my head in (collapsing) to much. To correct I focus on drawing with perfect erect form and then doing the necessary head adjustment. That usually quickly fixes it.
As far as plucking goes, luckily I've never had that issue. However the best advice I've heard is:
1) Best option: don't think of the release at all just let it happen (what I generally do)
2) It's like holding a bucket of bricks, just let go
3) think of relaxing the forearm not hand
As for transitioning from "proper" shooting form to hunting form I'm currently working on the same thing. The way I view it the bow and arrow is a simple thing at some level. pull it back and it launches an arrow straight every time where it's aimed. So it's us that muck it up. As long as I have a good linear (push pull - no torque) draw and the arrow is under my pupil, it will go straight toward the target. What I generally find is that the more away from an ideal shooting position I am the shorter my draw usually is and less my gap is. So basically if I"m kneeling or sitting or have a huge cant I get the arrow under my pupil and reduce my gap a bit. I still let the rest of my body get into proper shooting form as much as the situation allows.
A lot of people will say hunting is different from target shooting and form doesn't apply. I don't agree at all. "good" form is all about consistency. And what is taught as good form will produce the most consistent results. But you're exactly right that concessions need made to adapt it to hunting situations. I'm figuring all this out too but that's my 2c.