>> does swiss pass cover for travel to chamnonix and back by any route rail or bus?
No, only one route is covered – the Mont Blanc Express from Martigny. From Geneva, you will need to travel first to Martigny, from where the route is: Martigny >> Le Châtelard (border) >> Vallorcine (change trains) >> Chamonix-Mont-Blanc. It is all by train, except if you are travelling before 24 June 2017. Until 23 June inclusive, there is a temporary bus shuttle replacing the train between Chamonix and the Swiss border due to implementation of a new signalling system. You can see the route for the Mont Blanc Express on the Swiss Travel Pass validity map, which I have linked to below.
>> also we are planning glacier3000 and scilthorn…will mont blanc add anything or can we givr it a miss
In my experience, every mountain is unique in what it offers in terms of experience and views. It’s a personal decision which ones to visit. Time and budget will of course affect your choice as well.
>> lastly is the boat trip to yvoire from geneva covered in the swiss pass
According to the CGN website, the Swiss Travel Pass is valid on all their normal cruises, although Yvoire is not specifically shown on the Swiss Travel Pass validity map.
CGN website
http://www.cgn.ch/en-gb/content/faq.aspx
Swiss Travel Pass validity map
http://www.myswissalps.com/sw isstravelpass/validity
>> We have a 8 day flexi pass. So can we do the to and fro journey from Geneva to chamonix on the same day with the Swiss travel pass (2nd day of usage) ?
Yes, you have unlimited travel on a travel day with the Swiss Travel Pass Flex. To go to Chamonix, you must take the route I described above if you want to use the pass.
>> Someone had commented on one of the threads that the Swiss travel pass is valid to chamonix on the last day of travel. Is that true?
The trip to Chamonix via the route I described above is free on any travel day with your Swiss Travel Pass Flex.
Alpenrose