You modified the permissions on the directory structure on the client prior to mounting - all you did was set the perms on the mount point. Volumes/qtrees are created with root:root by default (if using unix permissions, of course), and the acls of the remote filesystem are what show up on the mount point after a mount.
You need to mount everything up, then change the permissions and ownership. If you then mount the volume on another host, the permissions will already be set.
That should be fine. You won't be able to modify the .snapshot directories because (like the error says) they are read only. If you look at the LVTEST and LVDEV directories and sub directories, you should see them with the permissions you specified. .snapshot will always be root:root:777 I think - but the snapshot content, under .snapshot/<snap_name>/, will mirror the permissions on the live filesystems at the time the snapshot was taken.