How far does a toilet flange need to come from the rough wall "no sheet rock just studs" to make it work out?

Depends on what toilet you bought, most are set for 12 inches from the wall but you can buy 14" too. If you want to stay with code the toilet should be 15" from the side wall.

Standard rough for a toilet is 12" from the stud wall to the center of the closet flange. Regards, Tom