...is the term used at Volkswagen for Normteile, since you refer to the NOLAS system of VW (my educated guess?) standard parts will fit. I am not sure about the other term... sounds like parts which are used more than once, i.e. screws, brackets etc. Possibly "multi or repeat application parts"

These are parts that are often more frequently used (fast movers), they remain the same (easier to store or manufacture)...
Hard to say w/o more context

Normteile are always "fasteners". They are called like that in production companies, because they, of course, must be standard parts, i.e. manufactured acc. to a special standard (DIN - in case of Germany).

I can't think of a good translation of "Wiederholteile" - I would understand it like that: parts, which are often required, which are repeatedly required and as such in my understanding they would include the "Normteile, fasteners", theey are repeatedly required to built any machine or so.