yes or noone would like dis game. get the demo from PSN Store
just get steam. it's fun and free anyway
yes you do as there is a driver than downloads with it called steam which needs the internet to run the first time installation So YES you do need the internet to play mafia 2 but only on the first installation then you can play offline
directors cut has all the dlc add-ons built in if you get it your lucky unless you like free roaming at the end of games
yes
Yes.