Travel from train station to/from hotel

For Zurich: Use the trip planner on www.sbb.ch that can plan trips to any street address. www.oebb.at can do the same for Austria, and www.bahn.de for Germany.

Obviously we can't give exact answers, since we don't know what hotels you are staying at. But Google maps will give distances and can suggest available options. But if you are arriving at the central train station in each city, and are staying relatively close, then a taxi is always easier than metro or bus if you have much luggage.

Just use a taxi. The price will be reasonable.

Look at the hotel websites. Normally they advise how to get there.