We do not recommend running different versions of DSS with the auto failover enabled. All updates are safe to perform. You can update Primary or Secondary in any order just make sure that they are in Sync to original position of the Primary.

So if you update the Secondary first then reboot the Primary will state that its Service is running degraded mode (this is normal). Once the Secondary is back up w/ the update then go to the Failover manager and click the start button and perfrom the update to the Primary.

In order to add additional volumes to be replicated from the Failover task fields you will have to stop the Failover Manager then add from the Failover task then apply and start the Failover Manager again.
The link below provides details on how to setup your failover – click on the 5th one down.

http://www.open-e.com/library/product-presentations/