Excellent map Hellhound, keep it up
One tool you might want to play around with for help in visualizing complex 3d maps is Google SketchUP. I posted a link to it and to a series of incredible 3d rpg maps a fellow named Nonethewiser had done for Goodmangames here:
Take a look. In None's hands, the results have been incredible. You've mentioned that the time you can devote to mapping is limited, and I don't know how difficult SketchUp is to master--but if you can, the results are well worth it.