Is there an easily downloadable offline help? It seems like all documentation is tied into MediaWiki and requires an online connection or a recursive download of the website, which does not seem to be easily done.
No, there is no offline manual. I'm afraid that this, too, is just not something that we should track in the bugs database. The bugs tracker is for tracking issues in Krita. If there's an error in the documentation, a bug is appropriate, but that there isn't a pdf ready for download isn't. We've been trying to create a system that would turn the wiki manual into a pdf, but the result was unusable.