Houdini is a very good name, I like it a lot and it fits.
I wouldn't worry about him not wanting to eat the grapes, they have very little nutritional value so if he doesn't like them thats ok, most use them for treats. Be sure to give him a wide variety of foods and you will soon learn what he likes and dislikes and the ways he prefers it be it cooked, raw, mashed or whatever.
Thats great that he can settle down for a nap in a busy household, that means he is comfortable and he is settling in very nicely.
I can't wait to see those pictures of Houdini napping, those are so precious.