I'll be honest, there's no quick summary sheet because when I tried to mock one up it felt more confusing than helpful; my layout skills are unsurprisingly self-taught, and that kind of density can be hard to use to effectively communicate. There is a table to reference for consequences and options for rolls in the book, but I couldn't figure out a good way to compress it and other reference details.
As for setting flexibility, that's very much an intentional part of the game's design. I wanted Detect or Die to be about a specific scenario, which could occur in all kinds of settings, with all kinds of mysteries. The amnesiac detective is a very flexible narrative!