Changing the labels for Node Referrer fields cause them to disappear

Situation:

I am making a music directory (of bands, promoters etc) which has a core content type of "directory listing". I am also inserting events, reviews and interviews into the site, each of which has a content type associated such as "review", "event".

In each of the reviews, events, interviews etc I have inserted a node REFERENCE field so that when a user is writing a review they can select the subject of their review from the events listed on the site. I have also changed the label on these node REFERENCE fields to more human titles (e.g. "Subject of Review" rather than "nr_review_dir_ent"). This all works fine.

The directory entries want to have links back to each of these so that when you navigate to the directory entry for a band or promoter there is a list of the events, reviews etc pertaining to them.

To do so I inserted multiple node REFERRER fields into the "directory listing" content type - each one listing the nodes of each content type (e.g. events, reviews) which link to that directory listing.

Problems:

1.) I don't know if this is strictly a bug / problem, but it took me a while to figure out that this was why my node REFERRER fields weren't showing up, and it seems like something that should be coded into the module: When a node REFERRER field is added to the "directory listing" content type it does not show up on any actual nodes UNTIL the cache is cleared manually with the Devel Module.

So if I add a node REFERRER field to list the events which that band are playing at - it's invisible until the cache is manually cleared. Then it appears. Perhaps the module itself could clear the cache when an operation which requires it is carried out?

2.) This is the biggie: When the LABEL for the node REFERRER field is changed in "content type > manage fields" (from something like "nrs_dir_ent_events" to "Upcoming Events") then everything seems fine - and when you do a browser-refresh on the directory entry node the label has changed as it should - BUT - when the cache is next cleared that relabeled node REFERRER field disappears from the directory entry node. It is still listed in the "manage fields" list inside the "directory entry" content type - but doesn't appear in any of the "directory entry" nodes.

If you change the label back to what it was and clear the cache again it doesn't fix it. It stays missing from the directory entry node. I have found no way to get it back - the only solution is to create another one and then delete the previous one... then clear the cache again.

This ultimately leaves me in the situation where all the node REFERRER fields for events, interviews etc. can't be given a suitable title, and instead have to retain the machine-readable default name which they were given upon creation. If I change it, they disappear.

Any ideas? I'm quite new to Drupal so I thought I'd flag it up here first in case it was an obvious thing in the code where a label is substituted for a machine-readable id or something and could be solved very quickly. Has anyone else experienced this?