I've always kind of wondered if it was actually possible/legal for a fourteen-year-old boy to live in a house with nobody except his dog. I know that over here in the United States, if both of a minor's parents passed away he would most likely be sent to live with other relatives or a foster family, but I'm not really sure if that was the case in Japan. Still, even without the question of legality, Suguru would surely have to pay for everything himself, and he doesn't appear to have any jobs aside from school. It's questionable whether he's actually paying Mahoro, but I'm sure that when he first decided to hire a maid, he intended to pay whom he hired. Though there is the matter of inheritance and the such... erm... I don't know. Is it possible/plausible?
And now that I think about it, Suguru's parents died years before the series actually started. I really can't imagine an eleven/twelve-year-old taking care of a house all by himself. Yes, the house was a mess, but just the fact that he was able to survive, live healthily, and go to school on time every day seems quite a feat for someone so young.