Hehey wait for me guys!
@TheExpert
As said before it's a close to UO system.
If you want a single click just do it then, this is not up to me.
If you want the left mouse button for walking just replace mouse_right with mouse_left in the player function, just as you like.
And in fact the character already does continue fighting, even if you walk away he'll recognize the last attacked enemy and continue attacking when he's back in attack range.
But maybe some kind of special attack/ spell should be in there so that the basics are predone, right.
@ulf
The animation problems at the stairs are described simple:
The actor has to pass the height distance end thus may get across the run-speed border and switch into run mode for a moment.
You can avoid this by making passable stairs with a flat collision block in it.
The damage numbers are just printed with draw text thus they have no connection to the object they originally come from.
That could be made, but you could as well create number-sprites (like I did in dragonrise) which may look much better than simple drawn text, and they'd be just around the position they should be at.
Oh and:
Thanks for hosting the game BoH_Havoc! 
I like the fighting system , I havent played UO , I havent seen it too , but this looks very good 
