Rail reservations--How and when to make them?

Thanks to this site, we purchased at $100 discount a Swiss Saver FlexiPass for 3 days' 1st class rail travel for 5 adults: Zurich to Zermatt March 22, 2011, Zermatt to St. Moritz April 1 on GE, and St. Moritz to Zurich April 2. Some rail schedules are visible online and sometimes an error message says nothing can be done until 60 days before travel. How do we make the necessary reservations? We arrive in Zurich at different times from different places. Will it be possible to make our reservation for Zermatt in Zurich once we're all together or must it be done in advance? What about Glacier Express? There's a 10AM train and possibly you can buy a full ticket now, but we only need reservations before seats are gone. I made a reservation request for GE seats in October but there was no confirmation. St. Moritz via Chur to Zurich also requires a reservation; when can we confirm our seats? Lastly, Best Western at Zurich Airport promises a 10% discount for Swiss Pass holders but they do not reply to email, and the discount is only available by pre-arrangement. Do we have the wrong email (airport@bestwestern.ch)? With thanks for your advice --