All your worries/questions can be answered by trying the builtin flight simulator in the Go app. You could try all the features of the actual bird in the simulator including rth and ioc functions.
Hey mate, did you manage to fixed this issue? did you try to "link/pair" the P3 and the RC manually( by inserting a pin into the tiny hole @ the bottom of P3) after the successful updates of P3 &RC?
Thats good Matt, I've got same setup as yours and just flown couple of times but haven't tried indoor flying, hows yours behaving in indoor flying? do you always leave the VPS switch on?