Neither - to the recordings You can batch-add them though by selecting the appropriate checkboxes in the relationship editor (if all of the recordings are by the same orchestra and conductor, just one click on the top checkbox for the album will do the trick).
Vocals, and then select choir. Similarly for instruments on releases with those, instruments and then piano or whatever.
For linking works, there’s nothing better without userscripts, but see The Classical Editor Toolbox for a list of userscripts among a lot of other stuff. For everything else, the batch-editing covers it.
Also, minor things but ideally the track titles would look like “Liebeslieder-Walzer, op. 52: 3. O die Frauen” or something to that effect And looking at the cover, the release title would probably be “Symphony no. 2 / Liebeslieder-Walzer, op. 52”
18 different part works?
Do you know that you can copy URL of these parts (right click C for me, depending on your browser settings) from the parent work, and then paste this URL in the relationship editor to select works precisely and quickly, without searching.
added the choir and the orchestra to their respective tracks.
changed the album title as suggested and added some more information (barcode e.g.)
the track titles were copied over from the already existing release in the group. As I added the relationship I guess it is not really useful to correct small errors there. How do you feel about that?
in my enthusiasm, I also added two aliases for the release group, with english and german as locale. maybe this was dumb? I thought then it would be possible to get translation if wished for..I guess then there is no need to do the same thing to the release, right?