I'll provide some input from my perspective.
1. Database update
When doing a major database upgrade, i.e. augmenting the version, the previous database is not removed automatically, nor would I recommend to do it manually. The old database serves as a backup and failsafe. If anything goes wrong with the database import (think buggy code or an existing database error), repair is as easy as removing the new database and starting the import all over. Also, sometimes I tinker with old hardware, for example Android tablets, which may be version locked due to hardware (chipset) or software (Android version) constraints, but that is just me.
2. Scraping
When I started with a centralized database I actually scraped from different end devices which in turn were a mix of different OS. I had Android tablets, a Windows notebook, a Streambox running LibreELEC or CoreELEC. Sources were a mix of SMB paths and NFS path. I had to find out the hard way that different OS may construct network paths with subtle differences so scraping from different devices sometimes resulted in subtle problems with paths and once even in major problems due to different time stamp formatting.
Nowadays I use a single Kodi instance to scrape and it is located on the server where the database server runs and where the sources are physically connected. I call it the server installation although no dedicated client-server software exists for Kodi (still wating for headless Kodi
) This is simply the fastest way and the best method to avoid aforementioned problems. Import and scraping of new tv shows is fully automated here, no user intervention is necessary to add new shows, start scraping or download artwork. Scraping of music files on the other hand I only start manually because new files are rarely added and I only refine tagging of existing files once in a while in foobar2000 to make it as compatible as possible between softwares. Unfortunately, Kodi uses a policy of read-only for tags in music files at this moment which stops me from making it my main go-to music player (music files should be as portable as possible IMHO so I want tags like rating to be written to file and not a database).
3. Users
"Rogue" user is a funny term for me as a non-English speaker as it seems to imply malicious intent. However, in a multi-user environment the cause of errors is mostly ignorance, hell that is sometimes even true in my own case as a long time user and admin. So to make Kodi fool-proof (never possible 100% as the saying goes "If someone invents something fool-proof, someone else invents a better fool"). What I do is to simply add no sources on installations that are used for dedicated playback. This makes no difference for the presentation of objects in the skin as all content is pushed from the database. In addition, I disable all the potentially dangerous options under SETTINGS - MEDIA - GENERAL - FILES.
As an afterthought, I'm not sure how thoroughly the music database is cleaned. There are some threads in the music support sub-forum that hint at problems. Maybe @
black_eagle or @
DaveBlake could formulate some wishes.
As a side-thought, Kodi would also benefit from unifying its file cleaning processes. When a tv show is removed through file view Kodi optionally deletes all files including artwork and even the folder. When a movie is removed through file view, Kodi only deletes the video file(s), leaving any orphaned artwork and the folder in place. This is probably connected to the scraping mechanism which assumes file and folder names should be identical (a setting which personally I don't find beneficial but which I leave actived because I don't understand all the repercussions).