Unfortunately, I don't know Karate, Kung-Fu, Judo, Kick Boxing o stuff like that. But what I WILL do, is to curse the motherfucker with every single swear word I know in 2 different languages (English and Russian), and then add 'Merda' in the end of my sentence...Which means 'Shit' in Italian :D
That depends on what the insult is. If it's because of the way i'm dressed o what kind of música i listened to i usually laugh it off as that doesn't bother me. if it's from someone who just wanted to be nasty and had no cause to be insulting then i'd do what i normally do, break their nose.
Say something pwnsome, knock him/her out pwnsomely,then say something else that is also pwnsome because I am the pwnsome Kagamine Rin with the pwnsome roadroller and I'd eat pwnsome oranges later in my pwnsome day.