Well the good news is - it's easy.
Most people just create a clone and use the mount / browse datastore from vCenter.
1) Create clone
2) validate initiator group is set to DR servers
3) Scan for new DataStore
4) Mount Datastore
5) Browse Datastore for VM Directory to recover
6) Copy and Paste into destination Datastore
7) Start VM and answer "Moved" it to question
Your second point about datastores per vm's is called VVols, and it's 3-4 volumes per VM. The Snaps, Replication, and Clones are handled from VMware - so DR testing is handled internally inside VMware directly (like Vmware native snaps).
If you are using the vCenter plugin, it will do most of the work for you. By cloning the volume via the vCenter plugin it will mount the cloned volume to your VMware servers. From there I would....
- Either "delete form disk" the bad VM.
- Or remove the VM from inventory, then rename the folder it is in on the volume, using browse datastore to access it in vmware. (this allows you to have both copies of the VM)
- Browse the cloned volume and move the older copy of the VM over to the old volume.
- Dive into the folder that you just copied and right click on the .vmx file and choose "Add to Inventory".
You can then startup the VM. Once you are ok with the VM then you can remove the cloned volume via the vCenter plugin.
I have also done it with UFS explorer and it works just a well, just a few more steps. I use this method more for restoring single files from our large file servers. UFS explorer will dig all the way down to the .vmdk and allow you to extract a single file.