4) Joe's Solution - While it was a dramatic moment and a big surprise to the audience, I think Joe had other options aside from suicide. He could have shot his hand off, making it impossible for future-Joe to hold the gun and kill Sara. It also occurs to me that everything Joe knows is also known instantly by future-Joe, right? They make reference to this when future-Joe stops short of killing the stripper's son because present-Joe has just seen Sid's powers and figured out that he is the Rainmaker. So, if future-Joe knows everything present-Joe knows, then the moment present-Joe suddenly sees the Rainmaker's creation and decides to kill himself, future-Joe should stop trying to kill the Rainmaker and Sara. Get it? Joe does not need to kill himself because the moment he recognizes that he created the Rainmaker, the threat to the Rainmaker is gone.