In todays post concerning professional abilities anoddlad and hugeowl raised interesting concerns regarding the fact that it might be extremely tempting to take at least one level of commoner in order to gain double carrying capacity. I agree. But...
..there might be a way around that: I have been pondering whether to give the first professional ability only to characters who choose the respective profession as their main profession. Since its inception JADE has the concept of both multi-classing and main professions. The first profession ever chosen becomes the main profession of the PC. So far this does not have any special advantages (except that you always can advance in your main profession, no matter whether you meet the prerequisites or not).
A logical extension to this would be to also grant the first professional ability (which should be special, important and differentiating to each profession) only for the main profession. Then you'd have to be more careful about choosing the correct starting profession and the starting profession also would have more profound effects on the course of the game.
One might be tempted to argue the same for the 3rd level professional ability - but consider the cost of gaining that ability... Let's take the following example: say, that you start as a ranger and would like to enjoy the benefits of requiring less nutrition like a commoner. When advancing to levels 2, 3 and 4 you'd need to gain levels as a commoner (1, 2 and 3) to gain that one ability. In exchange you advance only very little in your combat expertise, don't gain many hit points, gain very different skills and suffer from an overall increased experience cost for your second profession (if you fulfill the requirements to advance as a commoner at all - which is not that difficult).
So in my humble opinion that is plenty of balancing. What do you think?