As most hate mail is
I think my favorite part out of that one, if I have to pick, is "retared"...
That mail certainly looks like it was written by a "drunk retared" person
As for the whole "aboot" thing - it's just a geographical accent. Some Americans probably say "about" differently. I personally pronounce it as you said - "a bout", like a fight, rhymes with "a shout"
I do have Canadian friends that say "aboot" though. It's certainly exxagerated in South Park and the like. I noticed it a lot in Toronto, and it was one of the things I did to blend in - picked up some of the accent. It was funny, because I actually convinced a store clerk that Vanessa was American and I was Canadian when, of course, the opposite is true. But I did it with good usage of the word "aboot" and saying that Vanessa was "from the States" instead of "an American".
There are subtle differences in the way we talk, but they're there.