I just replacing a driver's side door on my wife car. When replacing the door I changed the key hole assembly. I notice that there are three or four wires on the locking mechanism with insulation falling apart. The wires were touching but at the time of repair I didn't think much about it. If I were you I would keep the fuse out until the door panel removed and inspection of the wires. Its a fairly easy thing to check about 2 hours.

Once you fix this problem if your are still have the other issues you discribe I would consider looking into the wire harness as the problem. I have an 86 wagon that has some strange electrical things going on. Blinker issues, dashboard lights, and the shop told me the wire harness needs to be replaced. $1000 if they do it, $400 for parts if I do it. I haven't tackle this one yet not sure what I am going to do.

I hope this help a little.