Hi!

My family (Wife, Daughter 1 - Age 2, Daughter 2 - Age 1) and I are planning a 4 day trip to Zurich and nearby areas accessible by public transport. I am very confused by all the options available as far as rail passes go. I have a few questions and will appreciate and help/guidance:

1. Do my daughters need separate passes?
2. I have read that it is possible to purchase a group pass (with 2 to 5 names listed on it) for a discount - does this apply to my situation, will I need to list all four of us on the pass, and where do I go buy this?
3. I have read that there is not a substantial difference between the 1st & 2nd class experiences (especially not one that justifies the difference is cost) - my question here is, if I buy a 2nd class pass, can I upgrade select journeys for an additional cost to first class? How would this work?

A couple of unrelated questions around travel in Switzerland in general:
1. I am hoping to carry two small strollers (umbrella type) and two medium size back packs (with all of the baby food, diapers etc.) - Is this going to be an issue with booking 2nd class tickets?
2. Will we need to carry car seats with us (in the off chance that we need to hail a cab etc.) or do taxis have special permits that will allow us to ride in taxis without car seats for the babies?

As you may have gathered, a primary objective is to make the vacation fun for the entire family including the two young ones. Any help is greatly appreciated!

Thanks!