While I'm not sure about the laws in Canada, most U.S. states have laws
that prohibit charging more than a certain amount (usually $50 or so)
without the customer's permission. Most also have a law that prohibits
charging in excess of 110% of the estimate for the estimated work.
I'm not sure why spark plugs would be required to keep your warranty in
force, but it is about time to have them replaced (100,000 km interval).
Similarly, Edwin's exactly correct about the timing belt. But unless I
understand the Canadian warranty incorrectly, isn't it about to expire
anyway? If so, why would you need to do things that are recommended to be
done at 100,000 km to keep a warranty in force that expires at 100,000
Most likely the pulley the other dealer is speaking about is not a pulley
but a hydraulic tensioner for the timing belt. I, too, recommend
replacing this, since I've seen some of them fail. I consider it a case
of better safe than sorry when dealing with the potential of engine
damage. But there's no certainty that it'll fail soon if not replaced.
It'll probably cost you another $150CDN if you replace it while replacing
the timing belt, but about $600CDN if you do it separately because of the
labor involved with accessing the tensioner.