MMO Theory

[Encroaching Death]

I think I would have a mutually-dependent style of class makeup, like EQ does.

I'd have a crafting system like Runescape.

PVP system like Dark Age of Camelot.

Trading/Auction House system like Albion Online. Actually, scrap that. I like the community style market like P99 tunnel has it, but maybe with an in-game bulletin board where people could leave up when they're logged off.

I don't like mounts. No mounts. Makes the world feel smaller.

Little to no instancing either. Instancing might be some kind of achievable bonus of some sort, but not the norm.