Feb 3, 2013 - 2:38 PM
Hi ramram! I think that's a fine itinerary. On February 22, I'd actually spend the morning in or near St. Moritz as sightseeing options there are great, and then continue to Zurich with only a short stop (or no stop at all) in Chur.
This overview may help you out. In Zurich, you may visit the National Museum, stroll though the old town centre, visit the lake, take a boat trip, get to viewing point Uetliberg, and so on.
Looking at your current plans, a 4 day Swiss Saver Pass is actually too much, especially if you plan to stay in Zurich on February 23, not making any side trips. Instead, you can buy regular tickets Tirano-St. Moritz and St. Moritz-Chur-Zurich. For your last day in Zurich, a
Zurich Card may be economical. That's for sale at the railway station of Zurich.