I'd like to see you make a spell that can reverse time for all units for a set amount of time per level. Oh, and this goes for construction etc. Try to make it lagless.
Wait.... Can't do it....
It only takes more time until you get used to working with SC2.
That doesn't change the fact that I prefer extracting my MapScript.galaxy and editing it outside of the editor though... I also find working with actors aggravating. Also, many times if something doesn't work, you have to refresh the editor window...
Starcraft can do it?
I think not.