"I also noticed that none of the lights that are supposed to come on with the dash work, rear door lights, gear selector, etc... "
Looks like it maybe your rheostat or ground. You'll need to pull out your instrument cluster then replace your rheostat and solder a ground wire. Use the search function. There is a post that has pics and a step by step guide on removing the instrumnet cluster.
I have not personally replaced a rheostat, so I can't help you there. Sorry.
Good luck,
jrmd01@yahoo.com