Okay...
1. A lot of stuff (sneak attack, immediate actions) is "once per round". I'm a bit confused as to what they mean by a round. Is it the time between your current turn and your next turn (as in 3.5) or is it the combat round (in which every combatant takes one turn)?
I've generally taken it to mean between actions. For immediate actions its spelled out in the second bullet. For the sneak attack, I'm thinking that they only want you to make sneak attacks on your turn and only once (I could be way off on that one though)
2. The Healing/Inspiring Word powers grant more healing than just using a normal Healing Surge. What's to stop anyone from using this after combat?
Using an "encounter" ability during a "short rest" requires another "short rest" before its usable again. So the you'd have to rest an extra five minutes for each 2 uses of the healing ability.
3. If I understand correctly, you can take a move action and then charge as a standard action? Allowing you to completely bypass anything in the way?
If by "bypass" you mean move out to the side or otherwise gain a better line for your charge action then I think thats perfectly valid. You just have to move first because the charge ends your turn.