@catcake while I don't know much about manastorm, I was hoping to avoid the server cost of instancing by just randomizing the quests; I'm just guessing that instances cost more server power than no instances, but I have no clue how they host the game.
I've always found grouping with random people in the world to be clunky due to the need to explicitly invite and the fact that looting defaults to needing to roll for everything. That kind of stuff can slow down gameplay a little.
I wasn't looking to reinvent the wheel or create some amazing idea, but just refine and improve a 'sticky' part of the game for me. I don't know for sure, but I've heard that WoW implemented something from Guild Wars 2 where players automatically group together if they're in close proximity? This would completely fix everything if done the same way.