This is a 3 parter.
First, I think that when asking for controls, we should be given more buttons to play around with, like say, the right mouse button, or middle mouse button. Maybe more, or even all keyboard buttons, except for the escape key, which brings me to part 2.
The escape key should be reserved for canceling any controls that a script has over you. We need this because a lot of people forget to add things in their control scripts to cancel the controls. Also if suggestion 1 was taken, we might be stuck taking keys that get us out of control situations, such as the right mouse button, or the del key. This would not include money controls however, which brings me to part 3.
There should be a place inside of a script where the creator of the script can have the script automatically take controls from only the creator of the script. There would be way too much griefing if it was anyone other than the creator, and people like me who own gambling organized stuff are annoyed with the script constantly asking to control our money, when we're just going to say yes every time. Plus if suggestion 2 was taken, hitting escape to cancel other controls would not cancel our money machines.
So, there, that's what I'd like to see as far as control taking goes.