Just concentrating on ignition related items
My understanding is that the immobiliser plip and 10AS immobiliser can often be a bit of a problem and some perseverance to keep plipping to deactivate the immobiliser is sometimes required.
To fire the ignition the ecu uses a signal from the crankshaft position sensor. A faulty sensor, or dodgy connection, would cause a failure to start.
When you turn the ignition on do you hear the fuel pump run for approx 4 seconds ? If not it may be that the immobiliser is still 'on'.
I don't know how long you turned the engine over to check for ignition, could be worth cranking it for a while in case the GEMS delays both the ignition and fuel to allow the oil pressure to raise before starting. The hotwire just delays the fuelling, but the GEMS ecu also has control of ignition and may also delay that. (the hotwire engines have distributors, the GEMS engines use coil packs)
Other items
Some of the non ignition related failure points can be a dodgy fuel pump relay, faulty (or displaced) fuel pump fuse, and the inertia switch under the bonnet is activated or the leads to the switch have come loose.
