Get that old gas out of there and inspect the tank like derf said. If that sucker is varnished up, you'll either need to get it cleaned or replace it. Once you've done either one of those, put about 5 gallons of gas in it along with a bottle of Techron Fuel System Cleaner. Best stuff on the market. To me it sounds more like a fuel issue than anything else, since it starts and runs on the starting fluid. As for the battery dying overnight, that is a crappy alternator. Having worked for Autozone in the past and being the Parts Service Manager, I don't buy ANY ELECTRICAL or SENSORS from them because they're crap. Let them test the alternator for you and if it is indeed crap, which I suspect, go get one from NAPA or a GM dealership. DO NOT BUY ONE FROM AUTOZONE, unless that's your only choice. And before you take it out the door, have them bench test it to make sure it works properly.