Keep in mind that you can take the TBAS twice, and the second time people usually score higher. Although I feel that you will get a rockstar score your first time anyway, with your AFOQT scores and hours from your PPL.
Your GPA is low, but I believe that many people know that the GPA for engineering majors tends to be lower. If you can explain to them why your GPA is so low (working through school, difficult courses, etc.), I'm sure they'll look at you favorably, especially with those AFOQT scores.
That's my two cents, I'm a Prior-E and in AFROTC with limited knowledge on how the board would view this.