Since it's a kit, you shouldn't need any power tools and few cutting tools. Yes, a hobby knife and a big package of blades is a must. I'll second the Zona razor saw too. What hasn't been mentioned yet is clamps for gluing the bigger structures together, a flat building board that you can push pins into (plus the pins), painter's tape and rubber bands for holding things together while they dry or while you glue them, and the glues you'll need. Thin CA, medium CA, and 30 minute epoxy are the basics. You can use carpenter's wood glue instead of CA for most things, but it'll dry more slowly and will require a different building technique.