I had a nice stay in Lausanne at the Hotel Regina (found in Rick's book): http://www.hotel-regina.ch/.
For any Swiss hotel, e-mail them directly to determine availability and rates; I found that the online booking tools (even the ones on the hotel's own websites) did not show all the rooms and had higher prices than I got by booking directly via e-mail.
As for passes, unfortunately you have to do all the math. If you're only staying for a few days and only taking trains around the lake area (to Montreux and the Chateau du Chillon, say), a pass is unlikely to pay off. If you do not get a pass, you can get tickets good for travel from one zone to another that includes all transit within those zones. So, for instance, from Lausanne to Chateau du Chillon can involve a train, then a bus; you should be able to get a single ticket good for both of these. However, if you're going further afield than the Lake Geneva region, then a pass of some sort may be worthwhile.