Thank you for the kind words and the thoughtful feedback, really appreciate it!
First Pages is very much a preview of the concept and is deliberately quite on rails. A lot of the things you've picked up on, including the world around the book, the desk and the wider Scriptorium, are intended to become much more interactive in the full game.
The bookmarks also become much more important once the Codex opens up. Each run the book changes and adapts, and bookmarks let you mark pages/rooms you may want to find your way back to. That's where the choose-your-own-adventure side of Inkarn8 really starts to come into play. Unfortunately, as you noticed, that doesn't have much opportunity to shine in this short preview.
The point about drawing pressure is interesting too and definitely something for us to think about as we expand the combat systems.
From your suggestions, it sounds like you're really getting what we're trying to build. We'd love to have you join us on Discord, help shape the game with feedback like this, and potentially get access to testing the Chapter 1 demo as we develop it!