To be honest, I haven't read everything in this thread. There's not enough time right now.
Just regarding the octogons, why not use natural land features instead? With visual aids, you could determine which elements were prevailent. Dry parched earth could be fire. Swamps and farms: water. Rocky land: earth. Cliffs, canyons and open plains: air. I reckon you could come up with enough land types to cover all permutations of element, good or evil, weak or powerful, etc. Then all you need to do is build a natural world and let the magics work themselves out.
There was a terrain building function in StarTopia. You could increase or reduce each element over an area of land to change it. Earth caused flatland or mountains, water caused rivers and lakes, air affected soil wetness, and fire changed the temperature of the land. With just these tools, there were ten unique types of land that could be produced, and that was before applying mountains/flatlands. Making a world with these tools would not only look natural, but help provide magical formulae to the land.
