I know this is an older thread, but it really has merit IFF ( if-and-only-if ) when you enter an instance, a copy of your toon is copied over to an instance server and then player data is copied back to their real servers periodically; as well as when they leave the instance.
If RW were to implement something like this, I would recommend there be only 2 options for loot: Greed & Pass. No Master Loot & no ninja-needing.
My take on this is that when you walk into an instance, you would first enter a lobby where all the players who want to run that instance are sitting. If you already have your party set, then the PL can click [Enter Instance] & if not, the PL could invite people into the group prior to starting the instance.
This would take a lot of stress off the main servers, since instancers would be on another server altogether.