True, You will have to do what you feel is best. However, do keep in mind that this is the way that your xh sucks you back into his drama and keeps you mulling things over.
It's not your problem or fault that he doesn't have a car. It's not you fault he's living where he's at. He's a big boy and needs to learn that every action has a consequence to it.
True, please do not allow this man to ruin your weekend. If you must respond, sit on it for a while and then send a very short and to the point email and do be sure to remind him that you need your money to live on as well.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.