I am making a char for the Solaris 7 RP on these boards, and my character, being only 22, is also a bit light on xp; the life paths i took ate into INT and CHA in a bad way and i needed a 3 or 4 in most of the attributes due field prereqs in stage 3, so i burned most of my discretionary xp on attributes, so i ran into the same kind of problem. For a young char I think you pretty much need some negative traits to get xp to fill the gaps.
Remember two point though:
1. ?Not all of them are necessarily character flaws; a enemy trait just means you pissed somebody off, the grievence doesn't even have to be real, miscommunication causes loads of problems., and if the gm send them your way get rid of them and gain some xp. Having a bad reputation doesn't have to be a bad thing either, imagine interrogating someone when you have the reputation of Vash the Stampeed >:D, if you run into cops though. . .
2. They make a character more balanced and realistic; everyone has issues of some sorts, no reason a fictonal person shouldn't. Characters that are writen to be 100% undistilled awesome are known as Mary Sues; avoid them.
Personally, I think anything you give to your character should have a reason in his/her backstory, be them skills, equipment or traits, both good and bad. Heres the character I am writing for the Solaris 7 Rp on these boards as an example. First of all I wrote a bio before I even looked at doing the character sheet. I was forced to take XP in Enemy by the Tour of Duty module, but that could be justified of being favored for a promotion over someone else, or your unit putting the hurt on another and them despising you for it (in the latter case it could even be justified as them not hating you personally, but rather they would like to see anyone affiliated with your unit go to hell simply by association). I took unattractive and Compulsion/Hatred of Word of Blake based on my character's profile, however. Having half your unit killed and being lit on fire tends to color your view of a group, and scars are not good for stories when they cover half of your left side. I haven't gotten to the equipment stage yet, but I fully intend my character to wear long sleeves often, and once I get into the RP any blakists are going to be very much kill on sight for my character.