However, I'm struggling to understand how you want the various functions in your OP to work. The third one, batch add translated pages to the respective translated categories, makes sense to me.
But all the other ones seem like you are asking to batch create placeholder translations of pages meeting specified criteria, or batch creating placeholder translations of categories meeting criteria. I say placeholder, because in a batch process, there would be no means for anyone to actually translate any of the body content. It would be the old content with the wrong language selected. The only thing that would get done is the titles, but also with placeholder text like "Original Title (ISO-code)". Because of this, I'm not really seeing the usefulness of these functions.