Wikipedia will probably do the job

I would put the regular snow tire on the rear because the front needs the best tires you have.
It isn’t recommended to drive with different tires on one axle, but if the tires are of good quality and roughly the same wear you’ll probably be fine.

Would still recommend new tires per axle though

Plastic plate protecting components from mud and dirt. Probably snapped of at the point where a bolt goes through. Quick fix would be to drill a new hole and attach it with some tie wraps.

Or remove it at all. It isn’t necessary but just “better to have”