While the forum was down I had thought of one or two things but I can't remember them now. I think one had to do with another character ability... oh yeah! How about being able to mix-and-match certain abilities? Like a character that can climb on walls AND fly. And how about being able to edit how long a character can fly for? (It would be helpful if people were going to make a Cream skin for SRB2; she can't fly as long as Tails can, but she can drop out mid-flight)
How about being able to create our own time-unlocked features? that's a little extreme, though, I would think. Does the game have stuff show up for "character specific" stuff? Like if you're Knuckles and you set something to appear for Sonic, it won't be there for Knuckles? That way you might be able to create truely seperate routes through levels...