In the first chapter, it’s noted “The story has been corrected to British English up to Ch. 17, and further Britpicking is currently in progress (see the /HPMOR subreddit).”. Given your points, it seems like it’s not even thouroughly britpicked up ’til 17. I expect Eliezer to have written that note quite some time ago, so I’m not too hopeful about this still going on at the subreddit, either.
We copied the version from fanfiction.net two years ago. Maybe the HPMOR.com version is more up to date?
This version, HPMOR.com, fanfiction.net, and the pdf all have “honor” (without a u) at two places in chapter 7. I don’t think there is a more updated version.
Alas, then I guess the britpicking never properly completed.