Philip I don't follow you at all if you don't add templates telling that this profile is inside project xxx so don't touch it then you will have problems. I suggest you define an error in the Database Error Project where you define what profiles are inside your project and check if those have categories/templates....
We can't guess....
Your comments
1) Gedcom information
The gedcom info is in the change log
Question 1-1 how do you use it?
Question 1-2 when was it useful last.... the unsourced Swedish profiles I have seen that are from ancestry have no values in 99.9% of the tomes you click on them?
Question 1-3 on profile Van_Niekerk-977 you have two entries to the same gedcom or?!?. Why? if you check the raw GEDCOM file see link the first source is after 12904 lines so 90% of the important profiles look unsourced
I fast look in it its 50 notes with some text on 888 imported profiles so its very very unsourced and I can see no extra value in the file compared what was imported.......
Question 1-4 if the gedcom is so important why don't we have a direct link to it?!!? or create a RAW Gedcom template {{Gedcom|gu_id=1830}} so its easier to access it
2) These profiles do represent the children our COGH project covers
Question 2: How should someone outside the inner circle know?
Why don't you add a template? Research note or how do you communicate it? Should we assume if we have a profile outside Sweden that it's in a project and we can't touch it....;-)
3) As I had to reset all the biographies you had "edit"
Question 3-1: Why reset? to get the gedcom text info that is in the log?!?! Why not just add a link to the log if that info is important or a note this unsourced profile was imported using a gedcom that can contain more sources....please see log or have a Gedcom template as I suggest above that creates a link to the RAW file
4) Magnus, I know that what you did was within WikiTree rules to a broad extent...
I feel you invent your own rules and don't communicate them. I have been playing around for 2 years now on WikiTree and if you don't mark a profile or add a research note you will run into more problems...
M-1) Suggestion: define an error in the Project Database Error and check if a profile that fulfills your criteria to be part of the COGH project and yadayda and miss a category xxxx then its an error 999....(my understanding is that categories maybe will appear in the dump in the future...)