2012-03-01, 10:11 AM (ISO 8601)
Re: A complete N00bz first try at world-building...
I'm a big fan of that post, and that blog in general. My Blackwood setting actually started out as an attempt to apply the concept of Mythic Geography, but it's since grown into something different.
The only potential issue I see is the prevalence of mirrors in your idea. When I hear "jump through a mirror and end up in a wacky house," my mind immediately jumps to Alice in Wonderland, circa 1800s. You'd have to take care to craft the flavor of this element carefully, but if you do it could be a very cool addition.