I'm not sure about your first question. The cloning done by VSC in a NAS environment works on a VMDK file level, which obviously is inside of the LUN in a SAN environment. Perhaps the VSC guide will go into more detail about the provisioning and cloning requirements when using SAN.
On your second question - we've tried this kind of thing before but the problem is that VMware will not start a virtual machine if any of the VMDK's are not writable, which, of course, in a snapshot they are not.
Your other option regarding cloning of VMs is to use VMware's View Composer which allows, I believe, the creation of "linked clones". This, however, requires the enterprise level license of View and I don't think can be used in conjunction with VSC.
Hope this helps a little.
Richard
