Swiss Pass_Reservation necessary

Hi.
I along with my family (total 6) travelling to Swiss and have bought swiss pass. We have plan to go from Zurich to Venice. Just wanted to know, is it absolutely necessary to get the reservation done. We would like to catch early morning train on Thursday from Zurich to Venice.

Also, If we board the train without reservation, what would happen
A) Seat will not be together?
B) We will not be allowed to board as no seat available (How much is the probability?)
C) We will be asked to pay for reservation as it is a mandatory fee?

Also we are 4 days in Zurich, any suggestions as to which places to go and whether reservation is required for it.

Your help will help me plan my trip well.

Thanks in advance

Regards,
Rahul

Hi rahul, and welcome! Whether seat reservations are required, depends on your exact connection and the types of train you'll use. But in most cases, seat reservation for the international train crossing the Swiss-Italian border is obligatory. You can check the timetable to find out which trains require seat reservation and which don't. Seats can be booked through the seat reservation page, and an additional reservation fee applies.

Tips for your stay in Zurich can be found in this forum topic. The Swiss national museum is interesting too. And consider a day trip to lake Lucerne. For urban trips and other train trips within Switzerland you won't need any reservations (unless you're traveling in a special panoramic train, but that's not the case in or near Zurich).