Most Recent Update:
Fuel door NEVER locked with my aftermarket system. I did not wire it to (you're supposed to trigger lock+unlock at the same time), and as such, my fuel door only locked when I locked my trunk or driver door or something. This is not a problem.
My interior locks continue to be useless. The buttons, the driver door locks, the exterior keyholes do not trigger the central power locks as they should.
My battery also went dead overnight recently. I am not sure if that was becuase I may have left one of the aftermarket connections uncapped by accident (I fixed that) or because something in my car is draining current (which may explain why my power locks do not work).
My car currently draws 100mA or 0.1A when parked. Is this too much? I've disconnected the battery for the time being.
My next step is to pull the carpet below the drivers seat and see what's up.