To be honest i think where drug is right now is a good spot, with all due respect to your recommendation for drug, i feel like a secluded island dedicated to a cartel is a bit extra, the only realistic way of inserting is with a heli, if you come with a boat you're dead pretty much instantly.
The casino one is a good idea, it is a nice place, CQB is pretty dogshit on arma but would be cool if they switched it up for a couple restarts so we can give it a try tbh.