Wow, so many of these are exactly stuff that I had to figure out, but I didn't know anyone else had them! Anyway, here's a few I know the answers to:

- The hallway problem: The best way to mitigate this is to know something about the person. Then you can say "hey, how's that <insert thing here> coming?". Or, if your friend is wearing something interesting, say: "Hey, cool shirt!".

- The magical friendship word: You don't really formally become friends with someone, say the phrase and have a ceremony and all that. Just start conversation or invite them to something you happen to be doing, like grabbing lunch or going to that <x> that you know the other person is also interested in.

- Expressing sentiment: This isn't about helping, it's about sympathy and compassion. Of course it won't make the problem better, but it might make the person feel better.

- Genuine curiosity: Just say "I'm not trying to be an ass, I'm really curious". And don't sound sarcastic while you do that. Does the job for me.

- Participating in a conversation about things you know nothing about: Either don't come in with a positive / negative bias or just don't talk. If you do decide to talk, keep in mind there is always something interesting in everything. American Idol: "You mean these people give up their jobs for a year to just sing?" "I wonder why person <x> got selected when he's obviously a talentless moron" "I wonder what happens to the losers after the show is over".

Wow, just talking about this stuff is awkward and makes me sound like a robot. I guess some people get it naturally and others like us don't.