1. I don't think so, but could be wrong. Either way, not a deal-breaker - cheap install once it's here in Canada.
2. Yes. Unless you like to gamble with 10s of thousand of dollars. Personally, I like the nickel slots
3. You're fine with the US temp permit until you get it registered here.
Get a recall clearance letter from the dealership you're buying it from. Insist on it as part of the purchase, and ensure it's on letterhead, or has a business card with Porsche logo photocopied onto it.