When editing a classic release one often faces quite a few tracks sharing the the same composer, performer, and performance date. Here are some tips on how to perform several edits on the recordings and their relationships without opening every recording individually and performing the edits there:
Working on releases
1. release - Edit relationships In the toolbar on the right hand side, select "Edit relationships". This will give you a batch editor. Just tick the recordings you want to edit, then click one of the "Batch-add ..." links in the top. Mind saving your changes be clicking "Enter Edit" at the bottom.
Working on recordings
1. recording - artist relationships - adding attributes --- This is easy with the new relationship editor though the function is somewhat hidden. (You must re-add the the existing relationship with the attributes added.)
2. recording - work relationships - adding attributes --- AFAIK not possible without userscripts. Bitmap's MusicBrainz: Relate recordings to works from a release helpes a lot. With the userscript you are able to open the recording - work relationships on a single page then you can for example add performance dates.
3. artist credits of the recordings --- At the moment there seams to be no solution. Do you have any idea? IMHO this type of batch edit is very important with the new classical style guide where recordings should be credited to performers though existing recordings are credited to composers and newly created recordings (from the release editor) too. I think that also these edits should be available in the relationship editor.