I'm not sure if Driving helps flow. I know passing and handling do. I would think Driving would help OS, IS, and flow, but I'm not certain.
As far as handling helping rebounding, I'm pretty sure it USED to have nothing to do with it. With the implementation of "So-and-so tries to grab the rebound, but it goes out of bounds", I can only assume that the BBs added a handling check to rebounds, but it might still be random. I haven't seen anything official on it, so don't count any of that as what actually happens.