Lots of good ideas, lots of legitimate gripes. Earlier I used a world project I was doing as an example, not because I was trying to sell the idea or anything, but because it's the one I'm most familiar with and already contains a fair amount of these same lines of argument.
Overall - Is it a planet, that is, a sphere with an atmosphere and all that? Is it flat and on the back of a turtle? Is the turtle imaginary and deceased? Get a consensus on
what the world is from the major contributors. Assuming it's a basically earthlike world, "land grants" can go by obvious geographic barriers. Leave that definition a little loose, it's a planet, it
will have things that don't fit into neat categories. Also don't forget that weather systems, volcanic eruptions and such are not going to respect land grant boundaries. There has to be some sort of Kyoto Accord equivalent for this sort of thing, and it needs to apply to catastrophic magic use, too. And yes, that means the power gamer can't destroy everything with his worldwrecker spell, bonus, but here's the downside: That also means you as a GM can't use the catastrophic fumble
you prayed for for the guy who richly deserved it cannot be turned into "a vast space where the grass will never grow again, and is now used by wizards to instruct their apprentices in The Dangers."
Gods, etc. - It wouldn't be a problem except for the fact that it's
verifiable. Somewhere out there is someone who can say, "Yep, it's magic all right, and it's being drawn from _____ source." Therefore the latitude you have in your definition of "God", "soul", "angel", etc. has to fit within a common framework of rules
for that kind of magic use. Beyond that, why should you care what Gods they worship on the other side of the impassable mountains, or why? Those aren't the
real Gods anyway, right?
Races - Personally, I like this attitude
All I'm saying is forget the syereotypical races and focus on the WHY of the who, wich will allow for a consistent setting with the races it needs, not just the races of tradition.
In my own defense, the reason I have the races I do is because I started that world project in the mid 80s using RM1, the concept of "build your own race" was still years in the future.
But at the same time having a selection of different races for each area will result in instant chaos the moment there is trade between areas (Just cos it
says it's impassible doesn't mean it
is. A GM can't draw a box so big his players can't crawl outside it), quite aside from being a tough premise to swallow from the start. If you assume that evolution is slow, it kind of implies that a world old enough to produce sentient life is old enough to have selected such sentient life down to a comparatively few species. Personally I'd suggest 2 - 4 races present on a planetary scale, and beyond that "niche races" would require "niche ecologies" to support them. In short, you'd find the cities of the lizardmen in The Great Swamp, but lizardmen really don't do well anywhere else, that sort of thing.