1996 Dodge Intrepid bad battery and cable, or computer?

So, I bought this 96 dodge intrepid a couple weeks ago. I was involved in an accident 3 weeks prior, which totalled my car, and I needed to find a new car pronto. It seemed like a great deal. I didn't have much money to work with. The 3rd party insurance company hooked me up with a dealership and they found this car for me. It seemed to be in great shape for a 12 year old car. I payed $1750 plus tax.
well, yesterday I started my car and the power windows would not work, and I couldn't get the ac to stop. I restarted it, and this time neither the windows or the ac would work. I noticed the airbag and the abs lights were on. (They weren't on before) someone told me it could be a fuse. So we replaced the power window fuse and the one that controled the ac. It worked for a little bit. Later that night, it started acting up again. I read on the internet sometimes it's good to unplug the battery and let it sit for a few minutes, because it reboots the computer. That fixed it for a bit. I took it out that night. However, my dad noticed the positive battery cable was very worn, and the point at which it connected to the battery was rusty, and would not tighten up.
that brings me to this morning. My car would not start. Dad jiggled the battery cable, and it worked fine. I got to work, and I turned the car off, but I realized I forgot to roll my windows up, so I started it, and my windows wouldn't work, nor the ac. I'm back to square one.

a friend of mine who is in school for auto mechanics suggested it could be the alternator. But i'm not so sure. I have been hearing that dodges are made with shoddy computer systems.

i don't really want to deal with this. I may just hock it, get a few bucks out of it, and buy another car.

sorry for the novel, I just thought I should tell you every detail of the situation.

i would appreciate any advice you may have!

thanks,
gretchen