partly because he was the star and if I'm gonna watch a film with a self-contained gimmick like that, I have to like the solo actor more than I like Franco. The Tom Hardy vehicle (GET IT?) "Locke" is the most obvious other example.
But yes, "Spring Breakers" was a somewhat fascinating mess and his performance was a big part of the appeal and I always considered him the best thing in "Pineapple Express" (which had its moments but was generally disappointing), partly because he seemed like a real person (I've totally *met* that guy, usually in Berkeley). So yes, Franco's had his moments but "Disaster Artist" is my personal favorite.
As far as Tommy's money is concerned, I wouldn't completely rule out some sort of criminal activity but if that's the case, he almost certainly wasn't the "mastermind" but rather he hooked up with some shady characters, possibly from his home country, and benefited from their nefarious dealings.