Thread:Project:Support desk/Deleting "Category:Pages with broken file links" *and* removing erroneously-created not-actually-existing categories

So after the latest MediaWiki update... I'm not impressed.

I want to get rid of the "Pages with broken file links" category. It serves no purpose for me (What purpose does it serve anyway, given that there is already a "Wanted files" special page? Why do all readers of a wiki need to be notified of missing files with such a bright red link?!). I do not want to upload placeholders, I just want my non-file to be what it is until I upload a file, and my readers certainly don't need to see this "Pages with broken file links" category, especially since it preempts the categories that are useful for them. I tried the advice in a different thread about replacing the contents of the "MediaWiki:Broken-file-category" page with a single hyphen, and that did not work. Please let me know how I can actually get rid of it.

Also, when going through my "most-linked to categories" page, since I want to add new content to categories that are not highly populated, I almost had a heart attack when seeing almost 50 empty categories - I thought "Who has hacked my site, and left no trace of it in the changes log?!" - and then I looked more closely and saw that they were all misspellings, etc. that had accidentally been entered when I was typing quickly, and then corrected afterwards. But apparently they still exist?! (Only they don't, because they're red links.) Why is this list suddenly popping up, and how do I make it go away?

If neither of these things is fixable, fastest advice on downgrading to the previous MediaWiki version?