Ah, OK, you're just paranoid like me then
The electronics on these things are usually very reliable. The electrics like relays and wiring, less so. Sensors are also prone to failure, but if you've got a good cranking signal (which it seems you have), sparks, which it seems you have, and fuel, again you seem to have that...it relly should make some effort to go. Engine water temperature sensor is important to good running, but it should at least start even if that's gone totally OC. AFM again is improtant to good running, but it'll go without one. Throttle pot - yet again...it should idle more or less. You've probably eliminated all these anyway since you don't have any stored error codes.
Having spent a considerable time going round and round blaming all manner of unlikely things in the past myself, I find it pays to step back, and start again from the beginning. Assume nothing, especially if it's something simple you already tested! (ask me how I know....)
Crank trigger - check. Confirmation of this is that the pump continues to run as you crank the engine.
Fuel pump - check (we think). Slightly awkward to test for sure, but you can test the entire fuel system more or less by taking the return line off the pressure regulator and feeding it to a container of some sort. Crank the motor - if you get a steady stream of fuel, then you know the pump and lines & filter are OK.
Fuel pressure. If the above OK, you really need to get a gauge and measure the line pressure. Simple enough to 'T' it in to the high pressure side. Doesn't matter where really, anywhere between the feed line from the pump and the pressure reg is fine. I usually use the feed end of the rail myself. You should see around 3 bar at cranking. At normal idle, you'll get roughtly 2.5 bar, but really, it's not that critical at this stage as long as the numbers are there or there abouts.
Sparks - check we think. A confirmation of timing and spark presence would be a simple old fashioned timing light. Connect to #1 and aim it at the timing mark either on the crank pulley, or if you can get to it, the mark on the flywheel that should be visible through the hole in the top of the bell housing. Expect something like 10 degrees BTDC or so I'd guess.
Compression check - remove one plug at a time, do each cylinder in turn with the throttle wide open. Just unplug the ECU or remove the ECU power relay when you do this just in case(!) it tried to start. Depending on the condition of the engine, you'd want to see at the very least 150psi, ideally nearer to 200psi. Cylinders should be more or less balanced. Some variation is to be expected, you'll likely find 2 & 5 are down compared to the rest. Any variance beyond 10-15% isn't ideal but not neccesarily a big issue.
Checking the injectors are getting volts and switching has already been suggested somewhere - pop your 'scope on the low side of one injector and see what you see. Should be an active low PWM drive, rest is 12V, duty cycle at cranking will be pretty short - expect pulse length in the mS range.
I'm running out of ideas now.......
...and yes, those rear bank plugs are awkward!, but at least you don't have to remove the charge cooler or supercharger to get at them.......(obscure reference to my current project