I'm just going to post this here for anyone else who runs across this thread.

My general advice is for someone who want to ride safely in cold weather and winter, like I do. My definition is "no more risk than riding in the summer". If you're comfortable with the idea that "Eventually I'll break some bone biking" or having your bike slide out from under you at 15mph, this advice is not targeted at you.

1. Studded tires are the single most important safety item on your bike when doing winter riding, aside from a structurally sound frame and wheels. They even tie with your brakes working - working brakes will stop you in snow and on non-icy surfaces, but without studded tires your brakes are useless on icy surfaces, and without studs your front wheel can slide out from under you without any braking involved at all. And there are other ways to brake even with brakes - there's no other way to stay upright on your bike if you hit some ice and your tires lose traction. If the front tire goes out from under you, you won't even have time to react and put your foot down. If you're debating whether to spend money on better components vs studded tires, you really need to rethink where your priorities are.
2. If you're biking near or below freezing you need studded tires (unless, perhaps, if you're biking in some sort of desert where it never ever has any precipitation). No amount of plowing seems to keep the streets free from ice - some always seems to manage to stick around somewhere.
3. Home made studded tires sound cheap, but they're really only appropriate for off-road use, for a couple of reasons -
a. They have a *massive* amount of rolling resistance on pavement. Way, way, waaaaaay more than commercial studded tires.
b. The don't hold up. The relatively soft metal used to make screws gets ground down by pavement pretty quickly, and once it gets ground down even with the rubber tire they don't grip ice any more.
4. The cheap commercial studded tires, like Innova's, or any tire that uses a regular steel stud, are crap for regular winter riding on streets and bike lanes. The steel studs will get ground down quickly on pavement (people say less than one season of regular riding). Problem is, there's no warning - one day they seem fine, then one day they don't work any more and you find out when they fail. They could work if you actually check them all the time, but most people won't do that. I've also heard bad things about the quality of the cheaper studded tires in general. The "expensive" studded tires, like Nokian's and Schwalbe's that use carbide studs don't have this problem - their reputation is that rubber tire will wear out before the studs do.
5. Running a front studded tire is better than none, but a front studded tire isn't going to keep you from falling down in bad winter conditions. Of the other people I know personally who tried to bike commute with only 1 studded tire in the winter, they both had essentially the same experience. It worked fine for a while, I think it was over a year, then they both had a massive wipeout.

Just to be clear, as I wrote earlier, the OP's plan sounds fine. Good, even. He's nearly only riding the bike offroad so the studs won't wear down at nearly the rate that they will on-road. And he is using studs. As long as he realizes that he needs to keep a watch on how badly the studs are wearing, and that they wear out relatively quickly, it sounds good to me.