@Moon @hidden mmo's are like the first big thing you don't write, you take a hard thing, and then introduce untrusted network calls on top of that, it always goes badly

so you go to the trenches, and borrow all the game programming gems and see which chapters cover the problems you're facing
each one is gonna have a big ass section with people talking over all the common networking and multiplayer woes and how they've dealt with them
https://archive.org/search?query=Game+programming+gems

also maybe http://ithare.com/contents-of-development-and-deployment-of-massively-multiplayer-games-from-social-games-to-mmofps-with-stock-exchanges-in-between/