That grammar thing can still be a mystery:
The store contains the usual Barnes & Noble cafe, so I guess this means the people who deliver food and beverages to the cafe are to refrain from doing so now.
You can sell books (and presumably read them) BUT …
Dancing Treefrog 
I’m looking for any Midi files so that I can broaden my Synthesia library. Any websites that are at least guaranteed safe or have a very low chance of obtaining unwanted items?.
Sorry, I have no idea what sites might be “guaranteed safe”. As they say in the browser security world, “Only visit trusted sites” (while neglecting to say that no site can be trusted).
I’d start with the Internet Archive, here’s a search:
https://archive.org/search.php?query=midis%20AND%20collection%3Aopensource_audio
What do you mean by “low chance of obtaining unwanted items”?