I wouldn't change a thing. The only workaround until EA figures out if they want to acknowledge and/or fix this problem is to focus on your player types (which you can change).
My scheme is all goofed up from what I selected, but I'm still using the playbook I selected from the beginning regardless of what the screen says under schemes. In the meantime, just make sure your player "types" are where you want them and focus on getting guys that match the player type. This is what shows up as "good" when matching schemes during free agency and supposedly helps earn more XP for the players that match your style.
I also would like to be able to change the star/importance rating of each position but it's less important than just being able to update schemes. I think at this point I'd just be happy with an explanation from EA on many of the questions I and others have asked in this thread.
The main concepts/questions within this discussion is alive in these very forums in something like 5 different threads because a lot of people are having the same issues but absolutely no one has an answer. That doesn't happen very often around here.