Eres

[whisperwind1]

Also, the whole world, the surface at least, looks like this: The middle is Avar, North of that is Everfall, East is Manakat, West is The Imperium, and between the two are the Broken Moon Isles. The large continents are primal things that I haven't got into yet.

So my question is why do you have so many continents and supercontinents? I think perhaps you're underestimating the relative size of North America, because 5 North America sized landmasses would already account for around three fourths of Earth's total land. Adding the supercontinents into it and your setting would effectively occur on a planet the size of Jupiter, which is an XBOXHUGE amount of space.

Now I get that you want to go for big, and that's fine, but keep in mind that most D&D style settings are set on planets about the size of the Earth, with comparable landmasses. Relatability of topography and distance aside (after all Dark Sun has like, one ocean), the fact is the amount of space your setting has means little in the context of an RPG setting. To explain, most players will not care about size and scope, they'll care about interesting fluff they can use to make characters or raid tombs in. The fact is writing reams and reams of setting materiel is pointless if most of it is never going to be touched by the players.

My recommendation is that you can keep the five North Americas, its a great number of continents, and then give them general writeups, nothing too deep (crowdsourcing is a great idea for this btw). Then simply decide which of the five is going to be your default game area, and flesh that one out more (get as detailed as you like). That way the players will appreciate the immediate setting, and for future adventures, when you visit other continents, you can simply repeat the process. In this way your setting grows organically without you having to write a 450-page monster that no one would want to read in its entirety. As for the underdarks and outer planes, well one sentence should suffice for now, and if they ever become the focus of the adventure, then feel free to develop as much as you'd like.