There's a lot of posts and it wasn't until last night when I watched the movie that I clicked it.

So at the end JGL sees Cid's path to becoming the Rainmaker after BW kills his mother and basically turns him evil, so he kills himself to insure that his mother isn't murdered and he can grow up to be good...

If that's all that is stopping him from being evil, how does he end up being the Rainmaker in the first place (in Old Joe's lifetime)? In Old Joe's life he kills BW initially and none of this happens so Cid's mother isn't murdered, yet he ends up becoming the Rainmaker anyway. Who is to say that's not just going to happen again anyway, regardless of if JGL kills himself or not?