Your first problem sounds like a lean mixture or IAC problem.

Having it just die with no spark sounds like a DME problem. Does the tach bounce when you crank it? Do a search on DME trouble shooting steps or page Ingo.

What brand DME relay did you install? It didn't have the initials URO emblazoned on it did it?

+1 on the URO relay - not a good rep

Have a quick look at your speed & reference sensor cables - if the insulation is crumbly, that's not a good sign.

Do you have a bentley workshop manual? Troubleshooting chart is a good place to start.

Put a bottle of dry gas in the tank... you may be battling an accumulation of water rolling around in the bottom of that tank. Sounds like you have a spark related issue, but the early post suggests you may have some involvement with fuel as well. Has the filter ever been changed out?