I just wanted to get this out quick before I forget: I strongly recommend filling out both weapons ability sets as early as is feasible. My original thought was to fill out the abilities for one weapon completely, with only minimal AP spent on the other until later. But then playing my Dragon, I decided to try it the other way, to get more variety. I managed to get a very strong single-target "deck" as well as a very strong multi-target/AoE "deck" relatively early, and am mowing down mobs. The trick is knowing which load-out I'll need for the next fight.
Also, you get an achievement and a cool jacket for each school of combat you complete on the inner wheel.