From what I've seen from the last few updates,the balance file is only written over if something new has been added or changed.So going to say vs 2.64 or something and using a 2.43 balance file would just cause crashes.
So what I do is simply open my old and the new file up side by side and simply copy my changes over to the new file.This way i can keep all my changes and also see anything new within the balance file from the updates.....and change that accordingly if I want.
Ice and Blood will be released in the US sometime durring the first qurter of 2010 I've heard.
Also I really believe the devs ment for us to be able to modify the game to how we like it with the balance file.
Think about it...it does not effect online play at all,and it is extreamly simple and straightforward to do.
i would like to point out that there is a way for it to affect online to
i wont post up exactly how as its done in 1 of the other topics i think before but in the autoexec you add a line at the start of the multiplayer part to load up the balance.txt and in thus you could(given you write it properly) cheat in lan and online for your self and others(so long as you reach a certain area first off and then others join they will get the benefit of higher drop rates and more xp or anything)
it was fun to do this once in a while with friends when online still worked