I want to prisonbreak my iphone, will it be regarded as hacking and thus the system will sandbox me?
Has not caused me any issues,my phone has always been jailbroken.
u only get sandboxed if u actually cheat in the game, whatever u do with ur phone is up to you
I agree. You will only get sandboxed when you cheat. 
. Do whatever you want on your phone because that is yours.
No.
Exactly.