Clarifications to datacake-sqlite readme

[canadaduane]

I'm approaching this project as a newcomer and have a couple of questions about the datacake-sqlite integration.

1. How does datacake-sqlite relate to sqlite? Specifically, can I query whatever it produces using SQL?
2. Is it possible to modify the sqlite storage using SQL, and if so, is there any expectation that these updates will eventually be consistent with other datacake nodes?
3. Is the double negative in these assertion sentences a mistake? "No document should not exist!"

Thank you!