Issues 1-5 already on Nikerabbit's roadmap
[11:05] <annew> Nikerabbit: if I remove all <translate></translate> tags from a page, will it cause any problems? I want to remove that page from the translations system altogether
[11:06] <Nikerabbit> nope, first you remove the tags, then you go to Special:PageTranslation to unmark the page, and then you go and delete all the related pages manually