15 lbs sounds about right. I can handle it while thinking about something else, if I could do that with an olympic bar I'd be Arnold ;-)

Getting on the ball: I do this like flat diving into a pool. Put my chest on it, arms forwards, roll until I can get my hands on the floor on the other side, then roll further forward into right position, while finding the initial balance.

Step: For now, 10" is plenty for me. Especially to get out of the habit of pushing. :-S