Geneva is much nicer and easier to navigate for the first time traveller than Lausanne BUT if you want to travel around the French speaking part of Switzerland it is somewhat out of the way.
If you stay in Lausanne then you will be centrally located for trips to places like Neuchâtel or towns on the plateau. The Beau Rivage is very nice, and near the lake. There is nothing between it and the lake, but there is a parking lot and a road before you get to the lake.
the Kempinski is not in Chardonne it is at Mt. Pélerin and is the Kempinsky Mirador. It has a stunning view down to the lake and the French alps but if you want to travel from there you will have to take the funicular down to Vevey, take a bus to the station and then go from there.
All in I think that Montreux is a better place to base yourself. Look at the Fairmont Montreux Palace or the Eden. Palace is the tops! And if you want to be in Vevey, then the Trois Couronnes is wonderful.
You could then travel from Montreux to Luzern via the Golen Pass route over Gstaad, Spiez and Interlaken...