If you are adamant about getting winter set-up I would worry about it for next year as by the time you get here (March) you won't need to worry anymore. Being cautious either way helps.
A good shop for maintenance would be Ivo on Columbus Rd. in Mississauga. There are some good BMW (Indy) shops all around so no worries.
A shop for winter swap if you wanna do it is SimplyTire in Toronto. (Keele/Finch) area.
Tax is only on non-essential goods. Our salary is also taxed progressively so the more you make the more you pay. You being out of town and working for a U.S. based company I'm sure you will get some breaks somewhere.
Shopping online is huge here too and if you still have a US address you may be able to get away with all the bs fees. It ain't so bad over here tho man....so just worry about your safe travel here.
As for areas to live, I find that Mississauga is a smaller version of Toronto, quieter, cleaner and calmer with less crime.
If stay away from Brampton and Scarborough. (Sorry for those of you who disagree)
I have a place in Sauga and love. I also have a place in Scarborough and hate it. Just my honest opinion.
Toronto (downtown) will be a busy area, much more fun at night, but also much more expensive.
Depends what you're looking for. And if anything, keep asking questions and we'll guide you along