Can I use the JR Pass on Nozomi Shinkansen trains?

Yes, but only if you purchase an additional 'Nozomi/Mizuho supplement' ticket. Otherwise, the pass is valid on all other trains including Hikari and Sakura.

What happens if I lose my pass?

You are out of luck. JR will not replace a lost or stolen physical pass. Treat it like your passport.

Is it worth buying the pass if I stay in one city?

No. The pass is designed for long-distance travel. If you are only traveling from Tokyo to Osaka and back, individual tickets are often cheaper.

How to Maximize the Japan Rail Pass for Long-Distance Travel

Buy your JR Pass voucher online at least 3 weeks before departure, then exchange it at a major JR station upon arrival in Japan. Use the official JR website or the station ticket machines to reserve your Shinkansen seats for free once your pass is activated.

Purchase the Exchange Order. Buy your pass through the official Japan Rail Pass website. You will receive an Exchange Order (or QR code). Do this at least 21 days before your arrival to ensure you have time to receive any necessary physical documents.
Activate the Pass. Take your passport and Exchange Order to a JR Ticket Office (Midori-no-madoguchi) at the airport or a major train station. You must specify your 'start date,' which can be up to 30 days in the future.
Reserve Your Seats. Once activated, use the JR-West Online Train Reservation site or the purple ticket machines at stations to book seats. You can book an unlimited number of seats, but you must scan your physical pass to finalize the reservation.
Navigate the Gates. Do not use the standard sliding glass gates. Look for the manned gate at the end of the line, show your pass to the attendant, and walk through.

Can I use the JR Pass on Nozomi Shinkansen trains?: Yes, but only if you purchase an additional 'Nozomi/Mizuho supplement' ticket. Otherwise, the pass is valid on all other trains including Hikari and Sakura.
What happens if I lose my pass?: You are out of luck. JR will not replace a lost or stolen physical pass. Treat it like your passport.
Is it worth buying the pass if I stay in one city?: No. The pass is designed for long-distance travel. If you are only traveling from Tokyo to Osaka and back, individual tickets are often cheaper.