I suggest this to solve one of the (IMO) big problem of the actual gameplay, based on TB, and not totally adapated for RT.
In TB, the AP cost is equal to the time that an action need to be made, while you can't do something else. So basically, for two player with the same AP (same rapidity of action), use 2 times 3 AP or one time 6 is the same thing. Sadly in RT, it's not, because the time during each animation your AP don't reload, and shot for example 6 times for 2 AP cost far more time than 2 times for 6 AP, which is not logical.
So here come the suggestion: animation time dependant of AP cost. To solve technical problem, it's basically that after the animation time finish, even if the graphical is not, you can act again and regen your AP. If you do another action, the animation stop to play the new action. If you do nothing after, the animation finish normally.
This would also allow the changing of weapon during fight (if you have one in the other hand) which is pretty useless right now because it block you too much time.
PS: I am high while writing this, so if it's completely stupid, just tell me ;p