1. Tom is terrified of having children of his own. Ingress is a delight and Gavroche has been a great son, but having an actual baby with Door is something that worries him, not the least because he worries about Door's health (his mother died in childbirth, after all). He knows it will happen eventually, but he's not in a hurry.
2. He writes in a journal still. No one knows.
3. Looking his best is part of what makes him feel powerful.
4. He loves magic. He loves feeling it well up inside him, he loves focusing it and making it do what he wants.
5. He really likes oatmeal. I don't know why. It's one of his favorite foods.