"Deh pefforza" is an expression used and created by Volpescu(also known as Vompescu Twonch), an italian Twitch streamer. It is used for indicate something that will happen surely, or something that is undebatable for who is speaking.
It can be used also without a context, for strengthen a fact or whatever.
wagwan is a jamaican patois or jamaican english way of saying "whats up"
piff means "high quality", and ting is the autistic version of saying "thing"
a bbm pin is the numbers you'd use to contact someone on the blackberry messenger