I looked at tickets with 2 or more votes and these were the ones that seemed relevant:
MBS-798: Add location and date fields to recording asks us to add fields to recordings to indicate when (and where, when we have location support) they were recorded
MBS-1424: Add a 'First release date' field to recordings asks us to add fields to indicate when they were first released
MBS-2021: Set recording times automatically has been discussed already - it involves auto-setting times for recordings based on track times, but it's unclear based on comments whether that should happen only for recordings that are linked to only one track, or if it should pick one of the track times (and if so, which release should be selected) or if it should also average the track lengths to create a recording length (and if so, which releases should be included). Automatically doing a small part of that is what MBS-2302: Set recording length when adding a disc ID is about. MBS-3987: Disable recording duration editing is related to the same idea, and asks for us to just make the durations based on tracks and not allow them to be modified by hand at all.
MBS-2234: New edit type to split recordings is not necessarily high-level, since it's just a tool, but I expect its usefulness will vary a lot depending on what we end up deciding a recording is.
MBS-4840: New column for BPM (beats per minute) for recordings is something else that I imagine would make more or less sense depending on what recordings end up being exactly.
MBS-1839: In NGS there would be benefit to giving track ids to tracks on a release says what the title suggests - that we should have a track ID to uniquely identify a track in a release.
Style and others
Plenty of discussion about the issue of what recordings actually are / should be has happened on the style list, IRC and elsewhere. Several relevant links can be found below this paragraph; the two main schools of thought seem to be the "masterists" (who want each of our recordings to apply to a specific master with a specific sound) and the "mixists" (who want to make full use of the relationship-sharing option recordings provide by grouping all versions of the same track together, regardless of who mastered it afterwards). The way most people are using recordings at the moment is somewhere in the middle, with different masters generally keeping the same recording unless they are clearly different in sound - but this is pretty subjective and doesn't seem to make anyone fully happy. There are also some people (the "performanceists") who want something above mixes to represent the actual performance.
 a diagram by Kepstin, showing Work-Mix-Master-Track.
User:LordSputnik/Track_System_Redesign a wiki page containing Sput's ideas on a replacement for the recording system (Work-Mix-Master-Track). Combines a lot of ideas from various IRC discussions.
 discussion on an earlier version of the above wiki page.
 an IRC log containing various editor's opinions and ideas on the future of recordings.
 more opinions and ideas from editors.
 a style mailing list thread full of ideas.