Thanks for all your help, W///. I got her all sewed back up earlier this evening. I fired her up and low and behold all systems go and limp mode gone. Codes still need to be cleared (CEL still on), but otherwise no issues.
I'd love to know what's up with these failing though. The old servo seems fine. I wonder if the sensor is just too sensitive. I mean what's so bad if the throttle linkage has a tiny bit more play than it did originally? I guess since its drive by wire with no backup they have it dialed in with very low tolerance to be safe. I did notice that the original part had "Siemens" stamped on it while the replacement doesn't. I wonder if they switched suppliers. Anyway, I am keeping the old one in case there's a fix later or a recall. It seems a shame to toss what is probably a 99% good part.
A gen-u-ine BMW eff-eight-zero with them tandem clutches in the transmission and that dad gum sun roof on the top-a da cawr.