Is it worth it to send in a 3 for AP Bio, or just forget about it and send in my other APs? Applying as a humanities major so its not the keystone to my application
Depends upon where you are applying.
Not sure about applications but it helped with credits at my kids school. A 3 only got elective credit but that can be important if you have a major with lots of requirements.
You can usually submit for college credit later (D1 sent one of hers near the beginnig of college senior year.)
Imo, you can skip reporting this one. But for poli sci, try to get in some related experience. Volunteer for a rep or get involved with some local advocacy (among adults, not just a hs club.)