Wow, great job approaching! That's one of the best starts to a PUA-journey I've ever heard actually.
Dealing with AA is half the battle for many guys, so you're golden right now.
I would really like for you to try to simply say "hi" and introduce yourself the next time you open a set, instead of using canned opinion-openers. The whole Mystery Method-scene is really in decline - it's more about being yourself now, having a smirk/smile on your face, and maintaining Eye Contact (very important).
60yearsofchallenge elaborates on this, you should read his material
Oh, your questions:
1) Try simply saying "hi" with confidence like I wrote, and get them to talk instead of you being the entertainer. I think this will make it a lot less weird.
2) Unless you have some specific reason for your friend to be there, I would say approach alone.
3) No.
4) You can probably smile more and be a little more silly if they're drunk, but I wouldn't think too much about it.