I'm procrastinating, so I'll take a shot at these.

1. First step is to sit your son down, tell him you're on his side regardless, and let him know he can talk to you about bullying, sexuality, or anything in between just as soon as he feels ready. Second step is to let the school's administration know that your child came home with a black eye -- they might have information for you (assuming you've got a good principal). I'm a big fan of relatively hands-off parenting (from experience as a son, not father), so I wouldn't take things any farther at that point. (Openly bringing up either issue, calling a p/t conference, etc. Those are for later.)

2. Easiest one on the list. Send an immediate /allmsg with an apology and an explanation, and forget about it. It's college. Shit happens.

3. Play it off, bring it up when you're alone with your SO. Explain why you thought it was rude, ask why she thought it wasn't/ignored it, ask if that's going to raise an issue. You don't have to enjoy the company of your SO's friends -- it just makes things easier. (Keep in mind that it can't be huge fun to "third wheel" for several hours, and that presumably this person's behavior has been normal up to the comment. Don't overreact.)

3.2 N/A Never snap at someone unless you know they're intentionally trying to hurt you. There's almost always a contingent circumstance of some sort, and there's really no point in making it impossible to patch things up by overreacting. There's always time to get mad later.

4. Confused. Not too many sports where someone on your own team can foul you. If they hurt you intentionally, two scenarios exist: a) other people noticed, and you can use court of public opinion to shame this person to tears, or b) no one noticed (unlikely, it seems to me). If the latter, make a scene. If it comes to it, stop playing. There's no way in hell I would keep playing a sport with someone who hurt me on purpose -- I've got real friends to hang out with instead. Additionally, that makes him the person who ruined his own team's chances by attacking their star player and making him leave.

5. I always laugh when that happens now. In my younger, dumber days I would sometimes intentionally instigate a car chase, because the recipients tend to panic and do extremely idiotic things. This is obviously a bad idea and only possible in certain situations.

5.2 Depends. If there are two lanes going one way, the right lane in my opinion can pretty much go however slow they please (American). Left is different. People who sit in the left lane going extremely slowly as car after car passes them just confuse me. If it's a single-lane situation and you have to get by, just honk, flash your hazards and gesture for them to pull into the shoulder. Wave apologetically as you speed by, and think nothing more of it.

6. Compromise! Add parts of their plans to your plan, mix ideas, schmooze, make them feel like they had your idea, etc. Talk to everyone privately. Politics.