Interesting post. Some fantastic hard-won knowledge and wisdom kindly shared here.
I want to add my own two cents as a photobook collector.
1. There is absolutely no requirement or convention toward organizing photobooks into chapters. I have ~700 photobooks in my library and I would estimate perhaps 4-5% at the most have chapter designations. Your pictures should work in the same way scenes in a movie or songs on an album flow from place to place. The full sequence of a book is one of the ultimate expressions of a photographer's art and to break it up into "Flowers" "Cats" "Landscapes" is to ignore the power of a fully-realized, blended and unified sequence.
2. There is no need to put a blurb on the back about you. People can Google you on their phone quite easily and learn about what makes you special. The less writing in and on the book the better.
3. Learn about photobooks and photobook culture. Buy some of the classics and learn the design language. Maybe you are making a typography, maybe new topographic-style landscapes, Japanese provoke-style high contrast freakouts, maybe it's a long-term project or the basis of a gallery show. You don't have to know everything about book culture but exposure to the art form will do wonders for transforming your project into something people might want to own.