There are a few missing commas in the bullet points, as well as some unnecessary commas in other locations. That does not instill confidence in a book that promises to teach grammar.
That is precisely the problem with grammar: some people like to be grammar police and they don't know the proper rules because they were taught incorrectly, or they simply disagree because of their interpretation. I am guessing you simply have a different interpretation of the rules.
I don't see the grammatical mistakes you are referring to.
Sounds promising, though a little short on the details of what will actually be in the book.
Looking forward to it.
On a related note, here is a nice course from Stanford about scientific/technical writing: http://online.stanford.edu/course/writing-in-the-sciences
I picked up quite a few things from there. (If you are pressed for time, you can watch the lectures at 1.3x speedup).
I'm building Quill, a web app that provides interactive grammar lessons. We are an open source/open content nonprofit organization, and we are working with a team of a half dozen volunteers. We are currently developing collaborative writing exercises, and if you're interested in building interactive education please reach out to me at peter at quill dot org.
Why would some these varied groups of people need a grammar book specifically for them?
I can sort of see why, say, a visually-oriented person may do better with a tailored book over a standard textbook, but programmers, designers, and bloggers seems like a wide set of people.