Replied in support! The text of my post follows.
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What if there was a compromise somewhere in-between of still having openly accessible role playing for all to participate in and a way to block out the grief'ers?
Perhaps there could be some sort of portal or entry-points at which players who wish to start a role-playing event. Rowdy night at the pub, fox hunt, visit the guild hall, picnic on a secluded bluff with a view, or heck - how about a guild or faction cookout in a large, open field somewhere, etc. Now give the person who launches the instance the ability to either lock it down and make it private/invite-only or leave it open and publicly accessible.
Imagine strolling through Argent Glade or Granite Falls and a message pops up as you pass the Inn -- or even better -- there is a pack of rowdy friends or drunkards stumbling around. They either beckon the player over or have quest icon active above them (perhaps a new RP icon could be created instead). You go talk to them and they tell you all about the great time being had inside, with a prompt as to if you want to join or not.
And if any grief'ers pop in and start a ruckus, the creator of the instance has the option of either ejecting them outright, or "calling the guards" (auto-flagging the perp for PvP so that those in attendance may show him or her the door. ;)
Heck, you could even have random events occur in these types of instances. A pub instance could have random brawls break out, random NPC's show up and drink with the group, etc
Would be quite fun, methinks. :D
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