Replaced the timing chain tensioner as suggested by Timm's BMW Repairs and Information. See Video:

https://www.youtube.com/watch?v=ktEctXhtufs&t=658s

This made my 4.4i snappy and happy again. It is sounding better too, less like a diesel.

I did not test the camshaft position sensors. I left the old ones in, and the two remaining codes: 22 Function, inlet Camshaft Control Bank 2
71 Signal Camshaft Position Sensor Bank 1, just went away after replacing the timing chain tensioner.

Timm reported in his video that the early warning sign for the tensioner failure was codes that were typically camshaft bank 1 over advanced. He does a much better job of explaining this than I ever could. He says if you change the tensioner quickly, you could save your guides from being destroyed by a slapping timing chain.

By the way, X5chemist, I still have my camshaft position sensors in the package. No need to test the old ones when they are working fine. I would love to know what the readings on a good sensor would be.

Thanks for everyone's suggestions and help. No codes on the X5 4.4i. Fun to drive again.