Regarding combats, I didn't considered the possibility to rest while fighting, I think we all agree on the fact it's unacceptable.
Same on the fact that monsters should get back to full health/mana if you rest.
What I had in mind by "abuse" was the fact of sleeping after each fights. It'd clearly diminish the need of potions.
DD limited it, indeed, but it wasn't clear as to why you couldn't rest for a while. Your character wasn't tired enough to sleep, I guess.
One thing I forgot to point out, you shouldn't be able to rest your your partner is fighting (for the same reason I stated earlier, i.e. the time-gap).
As for locking the bar in combat, I understand your point. Maybe it's not such a good idea to lock it automatically in combat, however I maintain the idea of locking it if needed (for convenience purpose, for it'd prevent the "drag-and-drop-by-mistake" effect).
Anyway, I doubt we'll often change our skills in combat, especially if a time-limit is imposed for each turns (which I hope will be implemented, to preserve a relatively fast-paced action).
It'd be interesting to add a second/third bar however, so that we could easily switch of builds and quickly adapt ourselves to the enemies.
