That's a Perfect everyday rider! If you haven't taken it for a quick spin yet, you're in for a treat. I Just picked up a Miyata 914 frame-set and slapped some Shimano 600 with bar-end shifters on it just to get a ride in. After 15mi, I already love this bike. Yours is in the exact condition to not worry about throwing it into a rack or tossing a lock around it against a sign or whatever, but it should still be a sweet bike to ride. It's funny that we're going through almost the exact same situation right now. Hurry up and get it road worthy!
Oh, as for your tires, I say if they're not structurally unfit, ride them until you wear the tread out. I've ridden old tires plenty just because you may as well use them up. No sense in tossing a tire with tread on it in the landfill.