Not sure about variables for owners or inserting in PM.
The owners/recipients would be listed in the online view (at bottom of first post) since they are in the To: part of the PM.
I agree it would be nice to see who is getting the PM in the body of the email.
I would love to see this fixed for all PMs as discussed previously
I also plan to add instructions in the request PM for users (wait for a reply/approval) and a link for owners (how to add users).