Thanks everyone for the replies...

I went out last night and tried testing out the fan. I ran the engine
until it was waaay too hot and guess what, the fan never came on. I
checked the fuse and it was blown, so I moved another good one in the
test it. The fan still didn't come on. Unfortunately, it was getting
late and I wasn't able to get the relay tested, but that's my next
step. It makes more and more sense that the fan was/is trashed since
the radiator was shaking violently. It just didn't occur to me to check
it since I guess it was running all the time (This is Texas, and it's
hot.

The plugs haven't been changed since I've owned the car (32k to 94k
now) so I'm going to change those out soon. I haven't cleaned the
throttle body, but will look at giving that a go over too since I'm
sure it's probably dirty.

Is it really best to go with a complete reman compressor? I would have
to have the system evacuated and all that stuff, plus the cost of the
whole compressor is pretty high. When the system was working, it was
blowing good cold air, and I also put dye in the system. I took my
blacklight out and looked for leaks and I couldn't find any. The
compressor didn't seem to be making noises internally. I checked the
relay for it, by the way, and it seemed to be okay (swapped another one
for it). Still didn't cycle. (And yes, I connected a complete DC
circuit to the compressor connector to test it the other day, and it
didn't engage the clutch, or even click).

I'm going to play with it some more.