Its kinda a mix blessing the freedome to do what you want but no one to give constructive criticism (or may not be able to act on constructive criticism). After all, someone was to go through the work to critique it and by the time that happens, i might be on a whole other page or direction.
I broke it up to 3 booklets and maybe I can bring the page count down. I have to be efficient and follow my own Analyst Training: My job is to Compress information - if the person wants to get the details they need to just look at my sources. Still I have to remember to bridge my sources with my conclusions, and that means stating and keeping track of my assumptions.
Book 1 - Introduction to The First Crusade. This is a very very narrow introduction to the Medieval Era. It is so narrow, that I focus on the highlights of what makes it wonderful without any of the build up going into the study of subject matter. Focusing on the highlights, I hope and guess that the reader may like the same things I do, as I take those things out of medieval historical context and make it simpler and approachable. The Draft Outline in this PDF.
I realized that in the Book 1 is where I should put the Sample Play and some of the lengthier explanation regarding what is a RPG.
Book 2 - Game Booklet - This booklet is sufficient for someone already familiar with Medieval Adventures (technologically 11C). This booklet begins with a short intro to RPGs, proceeds to focus on the aspect of Characters, and then Character Creation. Then ends with all the Rules; which is summarized with game physics/ world physics. Most of these rules are just gamification of many health, survival, logistics, and the combat system.
This is where I realize that in such a game we all draw from human limitations for all the rules; where we differ is how we interpret combat. In my interpretation its pretty much time-and-motion in a scale of time most humans average out in processing and action (increments of 6 seconds). Don't be surprised when I Gameify Variable Priority Training as an inspiration to situations like combat.
Book 3 - the GM's booklet of Running the First Crusade Campaign - actually Book 1 is a sandbox and pretty much everything you need to run the First Crusade (it has Everything!). Book 3 follows the tradition of Orcslayer and Harkwood with the writer Telling You Explicitly What to do and How to GM. This is going to be my take on Newbie GMing.
Of course in the end of the booklet, it shows you how to shake things up, improve and find your methodology (if you took management engineering then I guess you know how to improve any process and I'm pretty much using a layman approach to this), and evolve a GMing process that will meet your real world limitations.
By shake things up, I mean use the rules and tools already in book 1 to make more NPCs, keep the murphies unpredictable, and make the game re-playable.
So pretty much thats what I've come up with.
TL:DR broke it down to 3 booklets. Advance gamers only need book 2, New players need only book 1 & 2, and Book 3 is a GM book that tells the newbie GM explicitly what to do.