Welcome to the board!

The sensor you are referring to is called a Crank Position Sensor or CPS.
If the cable running down behind the engine head is frail and split looking, I would change it for peace of mind!
The CPS is the first thing that tells the ignition union that the engine is turning and lights up the other control units.
Once they come online, the relay you exchanged out also gets turned on.

Since you mentioned intermittent spark, there is another relay that you need to check.
It's called a power stage relay.
Basically it fires the spark coil upon the commands from the ICU.
It's located behind the battery and mounted on the inner fender well panel.

Since you have so many miles on this car. This guy is out of sight and out of mind so it may need serviced.
Some say it's the connector, others say the thermal paste on the base plate dries out which allows it to overheat. Your problem is on startup so cleaning the connector might help. If the car is dead, you clean it first and then fires up, that would be a bonus!

You say you have fuel in the rail. Are you confirming that the spark plugs are getting wet with gas or are you smelling gas?
Sometimes the the FPR's go bad and can flood the engine or just drain the fuel rail and cause hard starting.
This component is mounted at the front of the fuel rail with a vacuum hose connected to it.

Another thing to give thoughts too is the battery's condition and the timing belt age.

That seems like a lot of mileage on this car so it had to be taken care of over the years to get there!
You have had it long enough to know that already.

Keep us posted, we need entertainment from the 200 series.
(:-)

Phil