Have you cleared the faults and tried again? In case the errors appeared after mucking about with it?

Anyway....

You should be able to just push it down with your hand, although I have never tried it with the head on the car.

Use a socket on the crank and turn anti clockwise a tiny bit to align the inlet cam, then jam the inlet with a piece of wood or something then turn the crank a tiny bit clockwise then recount the rollers... (you cannot turn the inlet cam back using the nut under the camshaft position sensor cover to wind the inlet back, it will just undo)

I have to say the roller count looks pretty good.

 

Have you read the ross tech wiki for solutions ? or checked for chain stretch with vcds , i would leave the cam alone and look elsewhere before creating work.

 

It is possibly an error with one of the sensors. If you did not remove the timing belt or chain there will be no reason for the physical timing to have changed.
The cam sensor is within the field of work fir replacing the gaskets, check that it is correctly plugged in and the wiring is not damaged.

 

Closed the valve cover as-is and had a ride today, ~80 km, no fault so far.
Did some VCDS after the ride, so engine warm, for measurement blocks 90-94, see details below.
Any comment for these values? Not sure for 93-3: -16°kW

and

 

Still error
17748 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28)
P1340 - 35-00 - Incor. Correlation

but now intermittent and engine light doesn't come on for some weeks now.

During investigation I've lost locking clip for Camshaft position sensor (G40). What's the mating connector for this sensor (3-pins)?