Above The Clouds
Your reply/question is awfully mixed up, mixing "company manual" (AOC type) rules with old aviation chinese whispers.
So let me ask you for a reference for
and we can't do the above legally
Who actually said so?
mm_flynn has got it right (as usual).
Moving onto practicalities and safety (rather than legalities) there is a load of things one should or should not be doing e.g.
- using waypoints with hand entered coordinates (unless somehow verified beforehand) is not a good idea, especially in a shared aircraft
- one should still fly the published lateral track because the obstacle clearance is based on that
- be careful with GPS "overlays" for non-RNAV approaches, pulled out of the database, as these are sometimes partial-only, with segments missing (which is why I always fly literally what is on the approach plate, using the OBS mode of the GPS, and sometimes use VOR/DME in SIDs because it is simply easier)