Yes, you were correct - the crankcase vent lines have been replaced. Coils have been replaced under the CCP (should be all new coils), as well as spark plugs. I also changed the spark plugs - they were pre-gapped but I also double-checked them.
I'm on day 3 of trying to figure out how to remove the 3rd bolt from the intercooler
[is it possible that your auxiliary water pump (that feeds coolant to turbos) went out and dumped the coolant?] Very possible - the system does not appear to have a leak as the fluid level doesn't seem to go down. Although, I noticed a lot of evidence of leakage at the hoses on top - not sure it that is from fluid release under pressure, but I definitely need to change the rubber lines. There was, however, no evidence of leakage before it went to the stealership - I would have definitely noticed that.
[As far as the vehicle going into limp mode at WOT, that is usually (but not always) associated with either coils (which you changed), fuel injectors (which it sounds like you didn't), and bad/cracked vent pipes (not sure if this is what you are referring to as oil feeder tubes).] It is not always a wide open throttle that causes the fault, sometimes, just spirited acceleration - i.e. moving from 60-80 mph to pass. It seems that at the point the turbos should kick in, the fault appears. Vent lines replaced, and coils replaced - not sure about injectors.
[Do you hear any whistling under hard acceleration?] No whistling
Does the truck misfire/run rough when idling in limp mode? [I haven't driven it very far in that mode, I will check if there is rough idle - it "seems" to be rough just because it is startling to go from 8 cyl to 4 cyl]
[If your fault codes showed you misfire on one or multiple cylinders, but not all, you may have some faulty injectors.] I don;t believe the injectors were ever replaced under the CCP - I will ask about that.
[Did you leave those codes stored on your DME or did you erase them?] I am sure those have been deleted - the last code read only had the VANOS issue, but I have the BMW service reports that, I think, indicated the codes that were pulled.
Any advice on how to check the pump operation or DIY instructions on replacement?
Thanks for all the help!