If it is 0% interest I would use that and pay off debts, Good Luck
Do not use your overdraft to get more euros for a vacation. You should not be taking a vacation if you have to even think about using your overdraft protection for cash.
And if you have a car payment due, you should not be taking a vacation - you should take the vacation money to pay off the car loan before the economy collapses. That way you will have a car to live in.
Ok that was too radical. The thing about overdraft is that you should really never use it except in case of a DIRE EMERGENCY.
Don't buy things that you can't afford on credit. You are going to end up paying even more because of the interest rate on your card. A better option would be to not spend money that you know you don't have.
(question continued) Should I use a 0% credit card to pay off the rest of my car insurance now (and other Argos debts)
You MUST tell your CC company you will be using it abroad. They will put a block on it when they see the transactions.