um, no. You need a better plan like an actual solution to your problem rather than a suicide pact. You'll just get your friend put in jail. It's not actually legal for him to help you hurt yourself. You guys should stick around so you can be there for each other.
um, no I don't know. That's not okay. If you guys like to get rough you need to play safe. So at least have a safety word and sign you can do while you're doing whatever ...so he'll know you're in distress
Dude, if he's that crazy...you should get him some help or stay away
he sounds nuts, by your own description
Oddly I found this a bit hawt.
You probably should ask your best friend to reconsider, otherwise he won't have anyone to laugh at his stupid jokes. :D