you can just use primary-contributor here, no?

Same as above. Deleted the macro

You're making your substitute elements way too complicated. This should just be

<names variable="composer">
  <name delimiter=" / " name-as-sort-order="all"/>
  <label prefix=" (" suffix=")" form="short"/>
  <substitute>
    <names variable="author"/>
    <names variable="editor"/>
</substitute>
</names>

and ditto for all other substitues

Thanks, will correct.

This does nothing at all. I assume you want to move the

</if>
</choose>

down?

Hmm; I don't really know what this should do. Have removed it completely for now. Probably a left-over from an earlier version and not need anymore...

groups around single elements don't do anything

Thanks. Will remove those.

I don't really see the use of single-line macros. They likely have an (albeit tiny) negative effect on performance, increase style length and decrease legibility.

Ok. That's gone as well.

while legal as per specs, I'd strongly recommend removing any styling elements on names, bibliograph or citation in style -- it's a mess to troubleshoot.

Done

If you want anonymous works first, I'd make this explicity (i.e. something like text value="1" and then text value="2"` else -- both for legibility and because I'm not 100% sure the specs are clear on which way this should sort.

Ok. Changed that

Oh. After some discussions the department asked for "o.A." in the author field for anonymous works... So, these macros shouldn't be need anyway.