I am more concerned with "realism" (sic) than balance, that is, I believe, for example. a Knight should be able to Grandgmaster all melee Weapons and also Grandmaster, at least Chain, Plate, Shield, Body Building, Armsmater, and Repair Item. This is what he is trained for and why he is a "tank" so to speak.

I also believe that a Druid should be able to either GM all elemental and Body Magics, or Master them but be able to learn up to Master in Light/Dark magic. One or the other.

I always remove the Stealing skill from my Thief as I, personally, never use it and I also think it is a "broken" skill. But, of course, that's only a personal opion.