wonderful idea indeed. I really don't know if it's best to have an addon, a faceless addon or a library. Maybe a full flagged addon could be best, provided that it could help in fixing the bad alt's notes.
As is: showing the alts that doesn't have the right guild note, the "zombies" (alts of mains that left the guild, or changed their names) and such.
On the other hand I find having a full-flagged addon would probably delay it.
BTW, I borrowed some ideas from Chatter and I wrote a rough DoGuildInspection() function. I didn't test it tho, beside running the code snippet in wowlua (and it works).