Grapple: I would very much like to see grapple in the game. However, if it is a bonus action to grapple, then it should also be a bonus action to attempt to escape the grapple. If implemented this way, it prevents goblins from being able to bonus action disengage, so they'd either have to provoke an AoO or remain where they were.
Tumble: Also very much needed (I assume Larian will eventually allow us to move through allies freely..???). I even more agree with your suggestion of allowing you to tumble to avoid AoO. This way, they could remove the disengage component from jump!
Healing Surge: Eh. Slight disagree on this one, as it takes away from the fighter. Maybe if, as you suggest, they limit it to one HD per (long?) rest but then I'd want them to ALSO buff the fighter's 2nd wind to heal more (level-dependent healing?) AND remove eating food in battle.
Mark: Agreed that if implemented it should be a bonus action. Anything to stop the AI from ganging up on my lowest-AC character...
