Help for train travel in Switzerland

Are you using the SBB's website http://www.sbb.ch/en/home.html or some other site? You should be able to find pretty much everything about the Swiss Transport System there.

What time does your plane get in?

I looked on 25 March as a representative and saw an hourly connection Zurich airport to Guarda, leaving the airport at xx:13, changing twice at the Hauptbahnhof and then at Landquart and arriving Guarda Bf 2:46 later. Price without a discount card - CHF 66. Be careful not to read the 1/2 column which assumes you have a half fare card.

To Lugano is 4 and half to 5 and a half hours involving several changes, not counting the time you want in Samedan. Through fare without a discount is CHF 92.

Lugano to Milano is a very fast and direct journey. Just over an hour, regardless of whether you take the Regional or Express. It costs only CHF 29 on the express tomorrow. The Regional will be a bit less, and the Express on your date will likely be lower if you buy it 90 days out. But how much cheaper than CHF 29 do you need it to be?

For a regional Engadin pass I'd have to search around, and haven't done that.

Thanks Nigel!
these are the prices i got as well, so i will stick to the individual tickets.
I will research the Engandin pass as well, but not sure it is worth it since i plan to use only the lifts twice, the the postal bus seems very cheap already.

I does sound both logical and flexible to buy tickets locally at the regular-fare prices that Nigel found online. There's no deadline to buy tickets.