I'm Irish and feel I can connect with Marc's banter in a way because it's similar to the banter that I'm used to.
I think Marc genuinely likes Danny as a person but not as a housemate. He knew he wanted to win from the get-go and the big clap was fake.. because he was showing his overwhelming support for Danny, the 3rd placed housemate, knowing fine rightly that Danny (deep down) would be devastated because he always thought it would be Danny: the winner.