There's lots of good advice here. The best advice I ever got was: Choose Your Battles Carefully. Decide what's really important in the long run, and don't sweat the small stuff. You'll have to be fair and consistant in your homelife policies, and (even worse) you'll have to be a Good Example. I have three teens myself, and a "Do as I say, not as I do." lifestyle simply will not do. How could I realistically expect them to, say, put the dirty dishes in the kitchen sink, if I don't do it myself? So I have to get my chores done before I can relax, just like them (sigh). This makes me hold a slightly higher standard at home than I would if there were no witnesses, but I figure that if the leash is just *slightly* short now, when they go off on their own in a few years and they loosen their standards just a wee bit (and who among us didn't?), they'll come out just about right.
Get ready for the contradictions. Myself, I've been chewed out by the same kid for 1) waking him up so he could go to church and 2) not waking him up the next week, but letting him sleep in. And remember that stage when he was a toddler when he wanted to explore/wanted to hang on to your leg? That's been upgraded as well. My 16 year old "corrected" me (he's big on this) for asking for dinner menu suggestions. "Just put it in front of us, and we'll eat it." So much for treating him a bit more like an equal. Still, we do have fun with each other. I don't try to be a teenager, but I do listen to their CD's. So far mine haven't chosen any I'm uncomfortable with.
When there are guests over, I stay more or less out of sight, but in earshot. If there's a concern about plates and glasses, get some cheap stuff that you won't care about.
For sunlight, pull the drapes open, if the weather's good, open the windows for some fresh air. After all, you like it, and you live there, too.
For matters of hygene, I'd have to set some standards. Bathing and laundry are more important than the hair, though, unless it's so long he steps on it.
For better nutrition, maybe you could sneak the veg onto the pizza, covering it with extra cheese? If you try to force this issue, he won't eat it, and you'll be stuck with hard feelings and wasted food.
Since you both live in the same house, and he's old enough to take part in household management, there should be a partnership of some sort so you don't get stuck with all of the work. Mean old mom. Good luck. This is the hardest, but perhaps the most important part of the whole deal. This is where the house changes from your home to "our home" for him. There'll be a lot of negotiation, trade-offs ("I'll do this job all the time, if you do that one") etc., but what grows out of it is worth the sweat.
In the end, (I'm assuming there are no problems with drugs, gangs, etc), from what I've read of your postings, I think things will turn out all right for the both of you. I hope you can find some shared interests, teens can be great company. (I have do decide which jokes and drinking songs a lad should learn from his mother) Neither of you will die of boredom. Have fun, Mary