If my name is on the title for my son’s car, he lives at home and is insured under my insurance, has an accident, could I be held legally responsible?

Yes.

Yes, as a titled owner of the vehicle you have responsibility for any crash the vehicle is in per the Michigan Owner's Liability statute; however the mere fact of a crash doesn't necessarily mean there is liability as anyone who sues usually will have to prove fault, threshold injuries, etc. Each case is different and depends on the specific facts, so if any liability comes up you need to let your insurance company know of any claims and advise them of all the facts so that they can respond as may be appropriate.