Round Trip Toronto/Vancouver with Aeroplan Miles

I'm planning a 1 week trip in July to visit my sister and would like to minimize my out of pocket expenses. Standard op would be to book on Aeroplan, but their website shows flights available and the required Aeroplan miles redeemed, but not the extra charges (taxes, fees, surcharges) which may amount to $80 - $100 Cdn each leg. The flight would be a non stop Air Canada flight.

Visiting the United Airlines website, I can see that with the supersaver award, I could fly non stop from Toronto to Vancouver for 12,500 miles (or 25,000 miles round trip) and they show $22.60 for fees and taxes ($45.20 round trip). And the flight is the same Air Canada flight - AC33.

Questions:

1. Is the supersaver milage on the UA website the same milage as the Aeroplan for a long haul North American flight 25,000 round trip)?
2. Has anyone done this type of booking without any problems? IE: book on UA website to fly via their partner, Air Canada, from Toronto to Vancouver, using Aeroplan miles.
3. Not withstanding that UA website says $22.60 for fees and taxes, are there any additional costs that might surprise me at the departure gate?

Thanks for looking and any advise offered.