Had I read this earlier I would have saved you 5 pages of waffle. (imo of course
)
If nothing is showing up on T4 and there are no warning lights you are left with only two options.
High Pressure fuel regulator seal has shot through or your ECU capacitors have died in turn not firing the injectors because they are not holding a strong enough charge.
I have had
EXACTLY the same problem as this but it was never documented here, it was on the 'other side'.
HP regulator will not show up on T4, only a BOSCH specialist can tell you if its pressure is low (as can only a BOSCH specialist diagnose the caps on the ECU).
If I'd seen this, I would have got your car from Beaulieu and taken it to a diesel specialist in Poole. That is what you need to do. It has to go to a BOSCH service specialist for their flow equipment.
Glow Plugs will never stop the car from starting (by car, I mean our cars or any modern derv), in fact, Renault no longer have them.
Cam and crank sensors could have been ruled out in seconds if anyone had tried some easystart.
If you spray easystart up the EGR intake and the car runs, it is more than likely the HP regulator seal is shot and/or you're suffering from injector leakback. If it was cam / crank, the car would stop again immediately (same with ECU caps). Only in severe cases of HP regulator failure would the easystart not work, however, its possible that this could be the cause of you coming to a sudden stop.
Hope you get it fixed and that you now have a few more ideas to throw in to the mix.
My next move would be undoubtedly to get the car to a Bosch service centre. My local 'X-****' dealer didn't even know how to use T4. Well, they did, but only one person did. Remember, training on this equipment is long gone and is reserved for the experienced which soon turns into chinese whispers. I had to tell them what menu to access to check for pressure.
Good Luck