I'm not going to answer all of your questions right now, because I'm a little lazy.
But one thing I do know (and one of the main reasons I'm going to get an emag) is that the Emag has what is called a hybrid mode.
It uses a normal RT valve, except it says "emag" on the side.
Anyway, the hybrid mode allows for an electronic pull of the trigger with the retro return of the trigger! The best of both worlds. So the pull is super light and short because it is electronic, and then the trigger returns really fast, just like an RT!
You could do a search for "hybrid" on the boards to learn more.
Also, the SFL is "Super Funky Light" (or something like that ) As far as I know they are an extensively milled extreme Emag.
If at first you don't succeed, skydiving is not for you.