stefans idea's with villages could prove quite use ful. We could insert guilds like ancient india did in the Gupta Empire. One part of the island would be for militia, one for crafts men. each town would have a smithy devoting a kingdom armor/weapon/tool or item from that point of view. also i think that you should have stations around the isle so you could train a "kingdom class" this class would be your rank but as you improve with exp you get a higher rank. exp would be given for doing kingdom quests and they would require mental ability or things that all people would have a chance at. so then people could have lets say for samurai:
Theif lvl 10/ Ninja lvl 2 like multi-classing in D&D. it would also make game play more interesting.