[RIP]

What model year and engine? Are you seeing a service engine light? Either way, I would make my way to the closest Autozone and have them check error codes using a scanner. It's free.

Before you do anything make sure the battery is fully charged and all battery and starter connections are clean and tight. Same for the chasey and engine ground connections. The computers on these vans are sensitive to low voltage and voltage fluctuations. Strange things can happen if all is not well.

First thought would be a crankshaft or camshaft sensor for the stalling and no starts. Are you sure the engine was cutting off while rolling or could it have been the transmission was shifting erratically? If it's the later the output speed sensor would be my second thought. It is used to schedule transmission shifts and is the signal source for the speedometer.

Which gauges were "flickering" and what do you mean by "flickering"? When in the fail mode, smack the top of the dash a few times. If the gauges come to life and/or it starts, you may have a bad solder joint on the instrument cluster circuit board or it's connector. That seems to be becoming more and more common. You can test the gauges by simultaneously pushing the trip odometer and reset buttons. They should cycle a couple times indicating the instrument themselves are working.