You can be as offensive, stupid, brilliant etc. as you want as long as you stay on topic. If you're just resorting to personal attacks and (not even that indirectly) wishing someone to die you're not discussing anymore. So if that's your only contribution here than go off and fuck yourself.
It's all a balance and judgement is subjective and there's an huge gray area. I don't expect this post to be deleted since I am on the topic. Had I just written:
You're just a fucking offensive cunt, go stick a fork in a wall socket
It would (should) have been removed.
Use your common sense. The only "defense" is being a non native writer and writing something unintentionally offensive / off topic. In that case I suggest you improve your writing skill.