This app was mentioned in 8 comments, with an average of 2.13 upvotes
For the whole of Switzerland, you can use the SBB application. Link to iOS or Android / google play
There is also a ZVV transport application for Zurich, but you can simply use the SBB one.
For the rest of your questions, no clue.
Something that I haven't seen yet in the comments is the "plus" of getting the rail pass is that you get a lot of non-rail benefits. This includes cable cars, funiculars, and ferries (although not all of them, sometimes it is "just" a discount).
Also, keep in mind that the Swiss Pass will also include city buses and trams - this will be very welcome when you're visiting the cities (and villages, for that matter).
Have you downloaded the SBB app (for GooglePlay, but you get the idea)? I recommend doing so and then making some "pretend" trips. You'll just see just how convenient the transit connections are, and the app makes it super easy to plan ahead.
I can give you steps to save money on your Swiss rail tickets using Supersaver tickets (which I've used on my 3 Switzerland trips exclusively, up to 50% off)
Download the Swiss Federal Railways app (SBB, Android app)
Make sure you credit card can process Swiss Franc payments, store your card details in the app.
Search up to 30 days in advance. As you're almost here, search ASAP. Look at the whole days worth of trains, the symbol % on a line item signifies a supersaver fare is available. That being said, not all supersaver fares are equal and you should search for the timing that works for you AND is 50% off the full price tickets.
Profit. The app is also a ticket wallet, just show it to the conductor and they'll scan it. Check if the supersaver offer is valid up to Genoa as well (it might well be). The issue with these tickets are that they are for fixed trains (similar to flight tickets). I don't mind a bit of inflexibility to save money. Check the Trenitalia website for all Italian tickets (I have no idea what the best deal for IT is wrt train tickets).
The train is in the airport. Use this app: https://play.google.com/store/apps/details?id=ch.sbb.mobile.android.b2c
Edit: Or the official website https://www.sbb.ch/en/home.html
Also would highly recommend the SBB App. Available for both iOS, Android, and Windows Mobile