I know how to solve (chinese) farmer hackers and mastery book issues

Here's a silly idea.

Have scrolls and Mastery Books be marked with "One of a Kind." It'd sure would deter hoarding to some extent, right? xd

And as for meso sinks... a lottery system. Maybe?

That's a terrible idea simply because you need 7+ Scrolls to scroll any item, AND Mastery Books can fail, causing you to need more than one book at a time.