breaking through to my golden core of writing TTRPGs.
It's fine to cross reference the book.
As long as rules are in neat enough sections, labeled clearly, the player will find what they're lookin' for. Put the combat shit in one place, and the character creation in one place. Make a big summary, and make little summaries throughout. Stop stressing over "uuuuuuu it's not perfect" because perfect isn't done.
a done game is better than a perfect one.