Hi Bharad,
Reply on 1st Question: I have never seen ClaasCastException error at login but yes i've faced nullpointer exceptions many times while configuring Vintela AD SSO.
I have following questions in order to have a better understanding of the issue:
if you log in with default Enterprise Administrator account, do you still get the error in InfoView?
Did you try and regeploy Desktop.war?
Is the issue reproducible with multiple Enteprise accounts?
Reply on 2st Question: In your case it would not be required, because you are running CMSDBCOPY from the same old BO Server and not from a fresh/new BO Box.
To be on the safer side, you may stop old Input/Output File Repository servers >> Create new pair of file Repository servers >> Configure them by providing the correct local/network filestore location. If it is at network location, you will need to run these services with Network Credential (Service Account).
Regards,
Animesh Kumar