On my generation's sense of e-mail etiquette

I never know what to do when I read things like this post on excessively informal student/professor e-mail exchanges. Some thoughts:

1. I hate seeing improper spelling, grammar, and punctuation in e-mail. Not so much the kind of typos that creep in just because someone was writing quickly -- that's an inevitable part of life -- but I hate seeing "u" used for "you" and the like. My objection is not so much that this is unprofessional as that it sends a poor signal about my correspondent's I.Q. that remembering that the word is actually "you" requires visible mental effort. It's embarrassing in the same way that pulling out a calculator to add single digits would be embarrassing. I adhere to this principle in personal as well as professional life situations -- I am on the record as having said that I won't date anyone who can't handle using proper spelling and grammar e-mail.

2.Are there really people who write to professors using that kind of slangy diction? Am I just sheltered because the college and law school that I went to were fairly high up on the totem pole? Still, the law school with which the author is affiliated -- Brooklyn Law -- isn't at the top of the pecking order, but it's not at the bottom of it either.

3. Various people (okay, mostly Pnin) tell me that I am too terrified of authority figures for my own good. I usually mumble in response that I was raised by a German father, and that office hours would have felt more natural if only I could have called faculty "Herr Docktor Professor" without them laughing at me. One particularly tricky variation of this: I feel extremely ill at ease referring to people over the age of 35 or so by their first names. Yet actually calling one's colleagues or professional acquaintances "Mr. Smith" seems overkill in the opposite direction. So I sense that my intuitions lead me to be overly formal with authority figures. But I also fear disregarding my intuitions altogether, lest I go too far in the other direction.

4. That said, the comment about sending multiple questions in too quick session just seems odd. It has never even occurred even to me to worry about doing that.

5. The outline question isn't so much unprofessional as just... not pointed enough. Something like "I'm afraid I've misstated the holding of X case" or "I'm worried that my outline doesn't reflect how Case Y modified Case X. Could you help?" would be better.