2004 Cadillac Deville won't start? Any ideas on what's wrong?

[Steve-O]

Our 2004 Cadillac Deville won't start...It has about 96,000 miles on it, and its a V8. It's loaded GPS, wheels, etc. There's a story behind it not starting and I wanted to know if anybody had any ideas on why its not? Well we are on our way to a football game about 250 miles away from our hometown. It was running fine, except for the gauges wouldn't work.(The fuel gauge would never go down, and the miles on how far you can go before the tank runs out wouldn't count down either) Well we didn't think much of it because it was running fine. We had to go to the airport to pick up someone who flew in, and we were there for no more than 5 minutes, we left the car running and when we started to drive out of the airport parking lot, the engine started to steam. We got out and checked it and it smelled like anti-freeze just burning on the pipes, so we thought it over flowed.(We didn't think much of it, because the coolant gauge was fine and no dash light came on) We started back on our way down the highway and the car began to shift very very hard. We just drove to our hotel, checked in, got all of our clothes out of the car, had breakfast (Because we left our hometown at 5 in the morning, and doing all of this probably took 30 to 45 min.) We went back out to start the car and leave for the game and the car wouldn't start. It would turn over and would never act like it wanted to start. We have no clue what is wrong with it, we think it must be electrical because of the gauges not working and the car shifting hard. It also could be the fuel pump, but we are told by other mechanics its not the fuel pump because the gauges wouldn't have done what they did if it was the fuel pump. If you have any ideas on what's wrong, please help. Thank you to all who answer and took their time to read this.