Yes you can use Open Replicator (we do) no problem. Beware of your primary and secondary volume names, don't change them later, Commvault does not handle that good (no problem on the NetApp side though), as I have experienced as we switched from OCUM to Open.
Also, you have to create al the realtionships before Commvault can use them (follow the guide to the letter), and you do not associate a Snapvault Schedule policy in NetApp.
You create your Storage Policy as normal (both primary array and secondary arrays and the used SVMs should be configured in Storage/Array Mgmt, and they should be added as clients with intellisnap enabled).
We have 7 day retention on the primary copy, and only longer on the secondary snap-copy.
Create your vCenter pseudo-client, and your BackupSets as you need them. For the subclient, you have to consider how you are going to choose your VMs,we use DataStoreCluster as our criteria, and VMs are rewquierd to have all disks within that DSC (othervise you will catch those other disks to). Enable intellisnap for the subclient.
Create a secondary snap copy, with the real backup retention, and configure the source-destination SVM relationship for the Copy (especially if you use a fan-out with more snap copys.
The backup schedule for the VM's: I recommend disabel catalog indexing as that will take enormous amout of time for a large enviroment. Restores use "live browse" anyway.
Create the aux-copy schedule to run!
Then you need your VSA to be Media Agents to, otherwise it wouldn't work, we use ESX rpoxies from the production cluster to a separate ESX, with Intellisnap the ESX and VSA do not do hard work anymore.
After your primary snap-backup and secondary Snapvault has run, you are set for Restore and you do not need a backup-copy for this to work. You can ofcourse do the manual procedure to clone, and mount as you discribed, but Commvault does all that work for you.
When you initialize a restore, you can chose: singel file restore , vmdk restore, vmdk attache to other host or a full VM (to same or different place). Then it will start the "live browse", and actually create the snap-clone from the array that has the snap (could be the primary or the secondary, or you can force it to one of them), and mount it on the ESX you have chossen as proxy, and you will see it in your vC as "galaxy" DataStore or somethin similar.
Caveats: VMware tools is required for single file restore, and your Commvault user need to be able to authenticate in the host OS. For RHEL we use Quest and CV user has no privilidges in host, so all files goes to /tmp, and user needs to do a ssh login to the host for it to work.
vCenter tags are not part of the restore cain as far as I am aware. We run in to issues with vRealize sometimes.
We have 6500 VMs running on 4 NetApp cluster with 2 secondarys, and use intellisnap for about 5500 of the VMs (database VMs have disks in several DSC).
The load on tha backup servers (all of them are VMs on dedicated cluster) are low, but you do have to work a bit with the Aux-copy jobs. Follow the CVMA log in the Commcell for trouble shooting.
>>When the customer dont whant to make an snapcopy from the secondary filer because he says hey i have data on an secodray location and i have the primarary snaps thats enough for me <<
Do you mean they don't need a backup-copy from the secondary, (that is creating a "normal" streaming backup from the snap)? If so, yes they really don't need that unless they need to unspool the backup to, say a S3 layer or nedd tapes (bad memorys from those beasts).
I recommend you set up a test enviromen with a limited amount of non critical VMs, to nail down your specific processes as your envirmonet is probably different from mine (we use FibreChanel for example).
Hope that helps you, good luck, and don't hesitate to ask for clarification! :-)