Hi everyone! I'm sorry for the delay in responding! Ongoing issues not Pinto-related happening over here.
My friend David and I had the car over at his house. The brake light situation was fixed with a (slightly) different brake light switch than the one I originally installed and a new pigtail. However, we STILL have no taillights when the headlights go on, and when I put the turn signal to R or L, the front signals work properly, but the rear ones both come on, a la hazard lights. lol. There is power going to the sockets, but now we thing we need a new headlight switch. David also swears there's supposed to be a third wire going into that socket, but the wiring there doesn't look modified in any way. I'll look in my 1974 Ford Shop Manual and see, though.