Hell no. I'm not the type. However, I do have a Bulletproof/Fireproof/Explosionproof Elegy in my garage at Santa Maria Beach. That isn't cheating, right?
Early in the game, I got into a scuffle in the bar (of course, I did initiate it) so I can't play pool, never have in fact.
My far-flung suspicion is that the Photo-Ops could have been screwed up because I took some shots with th' camera with an unlimited roll of film (after completing "The Green Sabre" (Sweet Johnson)) but I started collecting snapshots icon with that regular camera.
I really am super surprised with the missing Snapshot icon. I paid a lot of attention to my maps and kept a list. So... yeah no cheats ever enabled.