Good god that’s a long starting list for your first post!! 
Anyway, welcome and here goes….
The controller and hard drive can be solved with a few different hubs but I had a lengthy conversation previously which helps explain that one.
@JiPenade has just answered some of the others and there’s no reason why you can’t have the MBP on usb 1 and the iPad on usb 2.
Hope we’ve all helped for now but feel free to chip in with anything we’ve left out!
Cheers
