Jan 19, 2016 - 5:08 PM
Hello HMIndia, thanks for joining us!
Great that you get to discover the Lucerne and Jungfrau regions; they're both beautiful. As for your questions: what's covered by the Swiss Travel Pass is explained in the Validity section of our Swiss Travel Pass page. It lists the major attractions and their discounts, and you can download a detailed coverage map. Moreover, pass discounts are mentioned in the Ticket sections of our attraction pages, such as the Rigi, Titlis, Jungfraujoch, and Schilthorn pages.
You definitely need a rail pass to save money. Both the Swiss Half Fare Card and the 8 day Swiss Travel Pass are good options. A Swiss Travel Pass is generally more convenient, as you can board regular trains, buses and boats without having to buy tickets. The Rigi is for free too, and if you'd plan to travel to Zermatt to see the Matterhorn, that entire trip will be covered too, as far as Zermatt.
A Swiss Half Fare Card could turn out to be cheaper, but that strongly depends on the details of your itinerary (e.g. your plans for May 7). So you'd have to finalize your itinerary first and make calculations to be sure.
Both passes can best be purchased as a print-at-home pass (without additional shipping fees) through www.swissrailways.com.
A day trip to Paris from Interlaken is not an option; you can check the timetable for details. You could travel to Zermatt and visit the Gornergrat for good views of the Matterhorn. It will be a long day, but it's doable.