Don't replace anything else until you get the fuel pressure problem fixed. A fuel injected car can not 'run on the fuel in the carburetor". No fuel pressure will ALWAYS mean the engine won't run on it's own
So you never hear the fuel pump run? Is that correct? Do you have a 12v test light? A meter can work but the 12v test light is better.
When you said you can hear the fuel pump kick on, are you hearing it click or are you hearing it run? It needs to run. It will should like a whirring motor and anyone with normal hearing will hear it but if you are not sure take off the gas cap and listen right there. If you can't hear it run, it won't start.
Upside down fuel pump relays tend to collect water in the fuel pump relay socket. That tends to destroy the socket and causes the fuel pump not to turn on even with a good relay. Was the socket looking like crap when you unplugged the relay?
At the relay you should have +12v ALL THE TIME on the Orange/Black wire. This is key on or key off. If you have to scrape through the corrosion to get the meter/test light to make contact that is most likely your problem.
Ok if you can find +12v at the Orange/Black wire - Take a paperclip - open it up and use the paperclip to jump between the Orange/Black wire and the Tan/White wire (it make look more like Pink/White) at the socket. Does the fuel pump now run? It should.
The black goop in the relay socket base is ok. That is the crap GM used to try to keep the water out. It won't hurt and will help, but it really isn't anywhere as good as today's dielectric grease. If you cleaned the goop out be sure to replace it with the di-electric grease.
AND MAKE SURE TO HANG THE RELAY UPRIGHT!
If you are having a problem finding the relay locally hit me up at firstname.lastname@example.org and I can sell you a good - used relay socket.
Also yes it is normal that either the Orange/Black or Tan/White wires may have two wires running to the relay socket.
[This message has been edited by phonedawgz (edited 08-04-2014).]