1. Name anything you want and you can have it ("name" in the sense of "say the name of the object"). 2. "Not a thing" is a more emphatic way of saying "nothing". 3. "To want" here means to be in a state of need. "They never wanted for anything money could buy" means that if something could be bought they could have it. They were never deprived materially. "I'd see to it..." means I would