Currently, traits are maxed out at 30 (which is far more than any beginning character ought to have), but it presents a problem late game. I usually have a ginormous pile of filthy lucre sitting around waiting to be wasted on whatever whims strike my fancy. Usually, this involves inserting absurdly expensive trait-adding items and buying them for all my girls to create my army of uberfrauen whores. When you hit the limit of 30, however, new traits disappear into the ether, never to be seen. This applies to traits picked up in the course of game play as well. For example, a trait-maxed girl will never become fragile, addicted to drugs, get an STD, or be broken through torture, to name a few. Now I don't suggest that you change things just to suit my whims (although when I lay out multiple millions for neural reprogramming drugs and physical reconditioning nanites to perfect one of my girls, I think I've earned the reward of having it work), but I can't see the logic of limiting the number of traits a girl can have, even for game-balance reasons. Limiting the number of traits a girl can start with is one thing, but whatever luck or misfortune bestows upon a girl in the game, she should keep, regardless of the number of traits she already has.
If you are concerned with save game bloat from having massive numbers of traits, you can get around that by storing the traits in a binary number, with each bit enabling or disabling a given trait. Convert the binary string into a hex value to store in the save file. Pick a large enough number of bits to start with, and you won't have to worry about running out of digits for traits. Of course, doing this would break the existing .girls/.rgirls files unless the game engine makes the conversion or someone releases a conversion tool.
The suggestion comes with the caveat that I am not aware of how things are handled on the back end, so it may be completely impractical.