I don't think that subtle hints are going to work. I have an idea that may require a great deal of work to begin with, but if it works the pay off will be worth it.

Either buy a pocket calendar or get a hold of his pda and enter in things that need to be done like garbage day, when the oil needs to be changed etc. Make a list of normal household chores and divide it down the middle (but be prepared to accept that his idea of clean and yours may be totally different). Include in your calendar a day off say once a month for each of you to be spent doing what you want to do.

As for your other "motherly" duties. Leave him to his own devices. Eventually either he'll remember to buy underwear or he'll go without. Either way HE deals with his own consequences.

The things you mention about hanging up on you and not letting you know he's running late. These are rude behaviors, be perfectly clear that he's not giving you the courtesy he'd give a perfect stranger and you don't appreciate it. Give him a bit of his own medicine. The next time he calls you, hang up on him. The next time you have to work late, don't give him any advanced notice.