I would say clear all codes Mark and see what's left or then take it for a run and see what comes back.

Dealer most likely plugged in and ran diagnostics and is addressing whatever is listed some or most of which may not be related to the issue.

NOx Sensor is used to help with emissions I had mine listed for replacement when I ran diagnostics but it had still passed NCT. Some guys seem to not bother replacing them at 400ish for the part. Supposedly over time if they are not replaced it can cause cat issues?

I replaced all my injectors recently enough due to rough idle and misfires, they were in both banks and the injectors had been upgraded so needed to do them all, no goodwill from BMW even though a known issue.