Me and a friend using game/ps+ sharing almost 2 years now.

What i do is, my ps4 (account that buying game and have active  ps+)  deactivated as primary but still using my profile to play. My buddy ps4, he will set my account as primary on his ps4, and play using his profile.

So far no problem, but sometimes message will pop out tell you applications will be close in 15 minutes because can't verify the license, but just ignore it, it will never closed the game.

Not sure, i only have 1 account in my ps4, later i try it and let you know.