Check to make sure you're getting voltage at the pump. Pull the plug off, put your probes on the -and + terminals, and have someone activate it while you watch. If you see power, then replace the pump. They're easy and under $30. If no voltage, try from the positive terminal to a different ground. If you read power then, you need to trace the ground and see where it is messed up. If still no power reading then you'll have to trace the wiring back. If the fuse is good, ground is good, but no power... might be a broken or chewed wire
If it doesn't have an aux port, or a cassette player, then get an FM transmitters. This will plug into the headphone jack on your phone, and transmit to your car radio. This is what I used to always do.
Information I've found says it is capable of up to 23ft/minute in reverse, so that's a little over half an hour. It is a very shallow trench with no rocks, so I'd dare to say it should take less than an hour, to be safe. That's 14ft/minute.
To test the switch, you need to access it. You'll have to open up the casing to access the trigger switch in the handle. Once you can access it, check for continuity across the switch. Then, with your proves still in place, pull the trigger and activate the switch. If it reads OL then the switch is bad.
There are multiple things that can be causing this. A fuse, the ac clutch could have issues, or it could very well be the pressure cutoff switch. It will be on the low-pressure side of the line set. Bad sensor or low on refrigerant. Then it could be wiring, or controls. Check the fuse first, then see if there's even any refrigerant left in the system.
Check the capacitor for the motor. Weak/failing capacitors won't get it going, but if you start it by hand and it takes off fine then the cap is the first thing I would check.