Anything from the game is effectively a template. Afterall, i would code a character then paste the code over into emerl making animation changes as required.
The bit too many people haven't got is that this was designed as a full game, so your character needs to make use of the inbuilt common1.cns file. And everything had 400 life. I can't remember why i did that now but it made sense at the time and everything is balanced around 400 life. If you chuck something in with 1000 it's going to pummel every single character in the game.
If you are going to pick on one character to use as a template i suggest amy, she is easily the most basic of all the characters. Or possibly Chaos, he's really simple too. Others are more complex due to the FX being required for emerl as well and the bomb or projectile being somewhat, awkward. Do NOT use cream for anything, cheese is a bit... special.
FX are all stored, globally, within the common FX files in data. No character has it's own FX in the sff at all.
I have very vague plans to come back to this but i'm still waiting on a few decent (by my standards) sheets. I want to add super sonic, espio, mighty, blaze and make use of that very nice E-101 gamma sheet. Super Sonic and Mighty also have OK sheets. Espio has a 1/4 of a good one, and blaze has absolutely nothing. Dark spine sonic is a no go, even if his sheet is good.