mind your caps lock and shift
putting capital letter in front of words is okay, but if all words in capital letter other than acronym (eg, FAKKU) is same as shouting, whatever message you write will still sound rude to other people reading it.
Fag is a general term for someone stupid, but it really means butsex between men.
Flame is where you attack someone in a forum or other internet community. Basicly, if I called you a complete fucking idiot, that would be a flame. Normally flames are rather long.
If you don't know what unrelated tangent it, you may wish to check your dictionary. It means talking about something that isn't really related to the subject.