Decide amongst yourselves what procedures you want to use when you dive. Politely ask him to be a part of those procedures, and if he refuses, then he's not a part of the group and you don't dive with him. Easy as that.
As for your checklist thing, people won't use it unless they specifically follow the procedures on the checklist. Since my pre-splash checks may be very different to yours, your checklist is worthless to me. My checklist would be worthless to you. Making a card with the BWRAF steps on it sounds like a great idea, except no one will use it, and it'll end up at the bottom of a dive bag as another piece of throwaway plastic. You're not the first person to suggest this. Hell, it's hard enough getting rebreather divers to use a checklist, getting recreational divers to use one is damn near impossible. So, if you want a checklist, make your own.
As for your checklist thing, people won't use it unless they specifically follow the procedures on the checklist. Since my pre-splash checks may be very different to yours, your checklist is worthless to me. My checklist would be worthless to you. Making a card with the BWRAF steps on it sounds like a great idea, except no one will use it, and it'll end up at the bottom of a dive bag as another piece of throwaway plastic. You're not the first person to suggest this. Hell, it's hard enough getting rebreather divers to use a checklist, getting recreational divers to use one is damn near impossible. So, if you want a checklist, make your own.