Solved the problem my own. Here's how I fixed it:
1. First, the permission assignment for the account used for View on my vCenter's Permissions tab was somehow glitched. When I attempted to change the assigned role to Administrator, I was getting the error: Call "AuthorizationManager.SetEntityPermissions" for object "AuthorizationManager" on vCenter Server "vCenter Server FQDN" failed, even though my account had Administrator role privilege.
To fix it, just delete and re-create that particular permission object. If you have any child objects assigned with a different role, just delete and let the role propagate from the parent, and then re-assign the role.
2. Second, it looks like the VMware View documentation is missing the permission required for rebalancing task. Rebalance will invoke the relocateVM_Task API to relocate the desktop VM to a different datastore, which requires Resource -> Relocate privilege. Ensure that you assign this permission to the role you're using for View Composer/Management. Of course, the alternative is to use the Administrator role, but if you're in the environment that enforces minimally-required privilege practice, that is not an option.
Thanks.