Thanks for taking the time to express your views quite clearly--I think this post is good for the world (even with a high value on your time and SI's fundraising ability), and that norms encouraging this kind of discussion are a big public good.

I think the explicit objections 1-3 are likely to be addressed satisfactorily (in your judgment) by less than 50,000 words, and that this would provide a good opportunity for SI to present sharper versions of the core arguments---part of the problem with existing materials is certainly that it is difficult and unrewarding to respond to a nebulous and shifting cloud of objections. A lot of what you currently view as disagreements with SI's views may get shifted to doubts about SI being the right organization to back, which probably won't get resolved by 50,000 words.