Yeah, what you said are really good ideas.
I'd also want to get to know more of the world, as you said. Like a different game exploring the nightclub, stuff with the smoker (is he the DEALER's doctor?), and other things like that. Maybe how the DEALER came to be the DEALER.
It definitely has enough stuff for the dev to flesh out the world and make it a whole "Buckshot Roulette" universe, if you will.