Depends on the quantity of misspelled words, in relation to grammar. No one is perfect. On the flip side, I can be just as offended by the spelling/grammar police. I'm pretty pissed off when I get a PM about one spelling error or poor turn of phrase (from those who are not real-life friends that are teasing me) when, for the most part, I am pretty conscientious about spelling and grammar.
In any case, I do try to spell correctly and use proper grammar on our profiles and in my postings on various boards and I prefer to read posts/profiles in which the writer uses the same care.
Same as above - an occasional misstep isn't offensive, but 20 of them in a post or profile is annoying to me.
All caps, all bold, all red or green or whatever makes my eyes hurt.
My spouse is guilty of the lower case as a "style". I loathe that. For crying out loud, he's an educator, and I don't think it's a good "example" at all to his students. He thinks it conveys his informality and his openness to providing help to his students. I think it conveys laziness in using the shift key and belies his skill and education level.
So my answer is yes, text style does mean something to me and can annoy or engage me.
The occasional well known acronym is not offensive/annoying to me. But an entire profile written in classified ad style is not enjoyable to read. YMMV, of course.