Paris and Switzerland for 10 days, looking for advice

I think your plan is pretty good as is. From Luzern you can easily get to Zurich airport on the day of your flight home. I will say that budget wise, once in Switzerland, Paris will seem cheap.

Hey if you like music and to party you are going to be in Switzerland during the Montreaux Jazz Fest
http://www.montreuxjazzfestival.com/en

Sam, thanks for the reply. I've heard Switzerland is expensive....is that mostly food and drink? The hotels I've seen so far have been reasonably priced (200-250 usd range). And I think we'll buy a 4 day Swiss travel pass. Are there any other high costs we should expect while there?

If you're comfortable with that price range for hotels, then you'll have plenty of options. You could spend less if you look around. Most purchases will be relatively more expensive than most of the US and Europe. For instance, 20SF is a common price for a personal-sized pizza in Muerren. Rick's guidebook includes lots of price examples. As another example, www.jungfrau.ch will show you ticket prices around the Berner Oberland in chart form – click on English, then Travel Information.

A 4-day Swiss Travel Pass (either flexi or consecutive) may not be the best fit for the time you're spending in Switzerland. Any way, some pass features will be different next year and you can't buy this type of pass until mid-January, so do more research then.

From Paris to the border crossing at Basel, buy a separate, reserved TGV ticket, available about 3 months out for a significant discount.

You could get away with a single night in Luzern if you only want to check out the old town, and not spend time on the lake, or go up one of the mountains (Pilatus). Just make an early start when departing Murren to give you the entire afternoon in Luzern. Then Zurich and the airport for departure the following day.
Lausanne or Montreux would be options from Paris with that extra night.
Alternatively, if you are considering one less night in Paris then look at the evening TGV Lyria service to Bern. You have virtually a full day in Paris before a departure at 18:23, and arriving in to Bern at 22:50. Explore the medieval old town of the Swiss capital the following morning before the short hop to Murren later in the afternoon.
Just in case you are not familiar with the geography of the Lauterbrunnen Valley - Murren is perched high on one side and Wenger on the other (with the Jungfrau railway). Choosing Lauterbrunnen as your base makes it easy to choose either side for your day in the mountains. Murren, however, does offer great views and good walking.

djp_syd Thanks for the reply. It looks like our toughest choice we be deciding where to stay between Murren, Wengen and Lauterbrunnen for our 3 nights on the mountain. We're active but not to the point where we're hiking all day from 8-5. I'd like to spend some time relaxing, checking out villages and riding some cable cars up and down.

Wondering peoples experiences staying in hotels in Murren/Wengen vs. Airbnb in a private home. Prices look similar for both choices.