Coming from a guys perspective I would just say your going to get a male stripper and touch him, and see what kind of reaction you get. Maybe its best for the both of you to do the tradional bar jumping and drink a lot.

Wow.
He REEKS of immaturity and future marital problems.

Leave him in Mexico and go to Canada!

Instead of getting worked up over something 3 years down the road, find out about what other traditions he is going to be living by. You may be surprised to know them ALL.

It's a big red flag to me he expect you to be okay with his tradition of having sex at a bachelor party. I would be more attentive and less blinded by love from this point forward.

Tell him in no uncertain terms how you feel about it. And do it now, even if it won't happen for 3 years. Since you have such strong feelings about it (and I agree with your opinion) it's only fair that you let him know how you feel.

Bachelor party: It is a small issue.
It is clearly bothering you, and he must drop it or down size it if he loves you. He might have a dance party, but no touch or sex. (How dare can he say he might have sex in the party?? He must to be too young or he was kidding.) You can be in the place if you want to. You have all the right to be in the party as fiancé. (Although I will not. I will have my own party with girls to have fun) No further discussion.

Your concern is not about Bachelor party but trust issue:
The bottom line is if you find out if he cheated on you, do not marry him. You cannot marry someone you cannot trust. Long distance relathinshp is not an excuse for cheating whatsoever. Will you allow him to cheat on you whenever you are away in future? No way. You do not want to know his past before you met him, but you should care about his being from the point you were together. Have a serious talk, and make sure he gets your point. Good luck.

I don't know of any worthy man having a raunchy bachelor party with strippers/prostitutes. In the past ten years, I've attended "pre-wedding" parties in which friends of the groom and bride party together. Sounds like you have a man that will look for any excuse to cheat on you.