If you're interested in doing anything with Minecraft where starting from the official client/server won't cut it, #mcdevs is the right place. I have no idea a

If you're interested in doing anything with Minecraft where starting from the official client/server won't cut it, #mcdevs is the right place. I have no idea about what the players want these days. The large-player-count servers I believe still use instancing and transferring players between servers to support those numbers. The other hard part is the game's mechanics. You'd need a lot of careful game design to reign in the destructible nature of the game world and all its contents. Minecraft isn't about questing and loot, it's about construction, and if you're not leveraging this you might be better served by making your own game. Large servers typically address this with round-based deathmatch or deathmatch-like gameplay, not really what you seem to be interested in.