OK. I am back from vacation and back to bmw work
Problem solved. I got a new used fuel rail with all eight injectors (for $50) and swapped it with mine.
I have no more starting problems. I will take a snapshot of injectors again for comparison.
It most likely one or more injectors had a small leak but that did not cause any roughness. The problem was only when starting the car after the engine was running for a while.
I assume a small amount of gas was flooding the cylinder and it was having hard time to start (10 or 15 sec cranking and weird firing). Always it was starting ok when cold which I assume the gas was evaporated and no flooding in there.