J.,
Some children have a difficult time with the kind of structure routine that your children seem to thrive on. Take a look at T. Barry Brazelton's book that explains the different kinds of temprements in children. He can't change this hard wiring, but that said, he should be able to adapt and find a happy medium while he is in your household, espcially if you guide him lovingly and with kindness. He may not sleep, but should try and have something else to do if he can't but he should learn to do it quietly, etc. You can find ways to help him cope with the structure in your home.
As for not listening, children have an uncanny way of setting us all straight when we say that once they learn the sublelties of language! If you mean that he does not hear, suggest that Mom gets his hearing checked, if you mean that he ignores what you say (and you are sure that he heard and processed the information, and the information was developmentally within his grasp) that should be delt with as a behavioral issue which is not out of the ordinary for a child his age. If you mean that he misses what you say and you have to say it over and over to get his attention, then he did not hear you so he could not listen, and that could be a developmental concern that should be watched carefully. Two and a half is a little young to worry about a child who is distracted. Get down on his level, and touch him to get his attention before you speak, and tell his Mom to keep an eye on him for other developmental milestones so that she can catch anything that may be an issue early.
If you are worried, have the Mom contact Help me Grow (www.ohio.gov) and they can help her decide if the child is developing appropriately. She needs to do that quick, the cut off is age 3!