Studded Tire Choices

1. Don't worry about that footnote. The original equipment tire size is for a tire with 86 load rating. As long as your replacement tires have that load rating or higher, you are good.
2. Depends upon whether you plan to hit something in the road which damages your tires, or not. I suggest you consider your personal driving experience to assess how likely that is.
3. No
4. Probably $15 or $20 per tire, but if you care, why not call around and find out for yourself?
5. I suggest that you look at the tires yourself to see whether the tread is wearing unevenly. For each tire, measure the tread depth at the center of the tread as well as the shoulders. If you see that the shoulders are wearing faster than the center, this means the tires are underinflated. If you see that one shoulder is wearing faster than the other, then the car would benefit from wheel alignment. This might cost $50 or so.