Later CDL engines respond to code better and seem to have slightly better fueling so I would leave well alone, pump wise if you do then Loba or APR, I wouldn't go near the Autotech seen to many fail
My wife's car did 70k on the original cam follower which was fine but changed as a precaution on a Stage 1, have seen issues but on the sort of cars I wouldn't touch with a barge pole
Each to there own but when you are at 2+ you need a diff IMHO and if manual upgraded clutch, or just buy a DSG R
