Daniel,
By profession, I'm a developmental book editor (ie, I help authors develop their books and new editions). I just read the first edition for the fourth time (it is amazing, by the way, how with each new read different passages illuminate and "stick," so that it is a different book each time I read it). I have a lot of my own personal/professional opinions on what would improve the book for the revised edition. If you want to send me a new outline, or samples of what you are thinking of adding and where, I'm happy to advise (for the benefit of all beings).
I'll go ahead and venture to say what follows. Although I feel I have benefited from the anecdotes already in the book, and those portions add credibility and authority to your more general assertions and descriptions (ie, it is clear that you are very advanced, have been there over and over again), I think I would steer away from very long excursions into your history midchapter. Having said this, I will add that I would really like to have lengthier, more detailed treatments of Fear, Misery, Disgust (where I've been stuck for 6 weeks now), and Desire for Deliverance--how to distinguish them and examples of how one might push through them and how one might get stuck in them. I can't believe how often you say in the book to keep practicing, yet what I have done since February has been to stop all practice except for Fridays when I sit with my dharma group at my workplace. Now that I've reread the book just this past week, all those passages and emphases about how one has to sit with precision and acceptance through all the worst the practice throws at us--they are jumping out at me and making me desire deliverance and resolve to reach it. Perhaps stories, not just of what happened to you, but of what happened to others you know of when they rolled up the mat instead of practicing would vivify and support your pleas to keep practicing through this awful stuff.
The first edition has some unevenness to it, on several levels. The substages of the Dark Night feel rushed through, and your videos from the Cheetah House are much less so (I recommend pulling into your edition the level of detail and clarity you effect in those videos, particularly on the DN, even word for word). The later chapters of the book seem to revisit/overlap with much of what was touched on much more briefly earlier, and I know that is because you are comparing different versions of the maps, but I think more weight and length should be shifted to the first presentation of your own (Bill Hamilton's) map. The other versions are really kind of appendix-like fare for geeks who already know a lot. Think hard, in other words, about your target audience, and then stick with that audience throughout: Beginners may be overwhelmed with more than one version of the maps, and you aren't really writing for the more advanced practitioner who already knows some version of these territories, right? I would actually move the other-map stuff to the Web site, and then lengthen, and slow down, the more basic content (your version of the stages).
The first part of the book on the Three Trainings is clear, even-handed in treatment, and consistently aimed at beginners. In the next part your pace becomes something like that of a runnaway train, and by the end of the book it feels like appendices are being crammed in just because you want to stick in everything you have ever learned "somewhere." Again, who is the audience, and would that audience benefit from silence on some content at their stage? Could you settle sometimes for a pointer to your Web site for more advanced info? I would suggest that you assume you are writing for someone who has not ever reached Equanimity or had any involvement with Formations. Probably most who continue to read the book past Part 1 have crossed the A&P, but my guess is that many of those people, like me, are stuck in the Dark Night and need something more like a technical manual for getting out of it, past it, to Stream Entry. Those past SE are fewer in number, and most of them are probably here on this forum already!
The other unevenness, besides pace and practitioner level, is tone and personna. You fling a lot of anger down on those pages and seem bent on an almost deliberate looseness and breeziness, both of which stand in stark contrast to the way you come across in private exchanges, on these threads, and in your videos. I suspect that the vitriol in the first edition was a deliberate choice born of your goal of uncloaking the Mushroom Factor. However, realize that the tradeoff is that you will alienate, right out of the gate, many beginners who are coming from a Western, psychologizing, emotional model of everything, including whatever dharma practice they've started. I saw this happen in a reading group I was in that tackled this book. All but two of the people in the group, one of them being me after I too got past initial resistence, just quit reading the book. They were put off by the tone. I think you can crush the Mushroom Factor without resorting to any of that tone. Your perspicuity on these threads has taken my breath away

many times, more so because you answered some highly agitated comments by others with calmness and clarity, with a lot of silence and space around your statements. I would encourage you to mine many of the explanations and responses you've given on this forum and put them in the book, maintaining the same voice you do here.
I've also been thinking about your question months ago about whether to go into more detail about the powers. I think I would NOT if, again, you are trying to reach as many people as possible out there who need help recognizing and traversing the Dark Night. My college-aged son may read the new edition, but I can imagine that anything smacking of magic will put him off. Since the powers are not necessary for getting to SE, again, I think I would consider that stuff advanced and ancilliary and think hard about how to keep beginners in your pocket until Stream Entry.
Consider writing a new preface that lays out your motivations and aims for the book. This would be the place to put all that stuff about the Mushroom Factor. It would also anchor you to have a statement at the outset about why you are writing this book, for whom, and what good it should do. You state well into in the first edition that your primary motivation is to prevent practitioners from getting lost in the DN for months, years, or decades. That is THE purpose of this book, along with helping people to SE because of the ripples of gratitude you felt when you reached it. Even if the Mushroom Factor retains some qualities of a rant, it will work better as something worked into a preface, where it won't distrupt the more measured tone/pace of the book proper.
I agree with Simon T.: MCTB has several competing books within it. Consider taking out alternative versions of maps, Fractals, and any other lengthy treatments of stuff beyond gaining SE, and save them for another book. That will give you more needed room to spend on descriptions, detailed techniques, warnings, and anecdotes pertaining to attaining First Path.