Excellent idea. I thoroughly enjoyed reading it and will read again and add to if possible. I would love to add it to new and existing campaigns. I have two thoughts about content. First, is high level cartogramancy, would strip the world of all mystery. No more lost cities, no lost treasures, nothing hidden anymore. This could be cool on the short term but detrimental on the long term. Second, I think that following the rule of precidence, a cartogramancer would not be able to locate traps with his ability unless he had a working knowledge of said trap (what it takes to install/trigger/disarm it) and possibly a focus item. Cool idea. I've got to take it for a spin.
I really ejoyed reading this article, as cartography is one of my favorite subjects, and this is a great rendition of the power of maps and map-making transcribed to fantasy. Just excellent!! And indeed so complete. The cartogramancer's equipment list, the maps and spells, all the wonderful detail! You know, I could never imagine that it is possible to treat this issue so seriously, but now I am all for it)