glock has a compatibility within caliber which means most mags from there other 45's will fit. exception is glock 36 and i believe the gap mags will not fit. don't know about mag release and slide stop but we have a resident expert who will be along soon.
There is no ambi mag release for the 30. I just sold mine last thursday so I could buy a gen4 19 and make it left handed. I know it sucks I liked my 30. Sorry. BTW my 19 is awesome. But from what I hear there should be a gen4 30 coming out so there might be the solution.