There are no rules about how you must fly. If you fly in a certain way you will no doubt be called Head-On (HO), ack-hugging, or ack-starring, chute killing, vulching dweeb and no matter what plane you fly there is always a person ready to say that the only reason you got him was because you were a Spit/Hog(F4u)/pony/109/190 etc.-dweeb.
That this happens is mostly because your opponent is frustated that he got killed and needs to find an excuse for this other than his own flying. Just fly the way you think is right, you are the judge of what you think is right.
When it comes to the radio, there ARE rules for what you should write. Foul language is not tolerated, but this doesn't mean you won't see people use it. If a person gets too offensive you can squelch him by typing
.squelch [Callsign]
Notice the dot at start of line, this is important as this is how you tell the program when you want to access one of its features.
About what all the complaints mean I can try to give a short course here for you

Ack-hugger: a person who will run and/or stay in safety from his own fields defensive anti-air guns, because of enemy presence.
HO: When shooting against an enemy coming straight at you. Popular in planes with big guns.
Ack-star: When taking off in a bomber with sole purpose to defend a field from attackers with its defensive guns. Can also be in the offensive role (shooting planes on ground at enemy field with a bomber's gunners)
Vulching: Shooting planes taking off/landing at a field that has had its anti-air guns destroyed.