I read this post from David Warlich with interest because I find myself in a similar situation with similar questions. Warlich is working on a book and describes an exchange with another potential author regarding public sharing of a future product. Both self-pubish their work. With Warlich’s visibility, self-publishing probably works. I must admit I would take the self-publishing route only as a last resort because I am unable to rely on the lecture curcuit to bring attention to my work.
The posts are really less about self-publishing and more about making the authoring process visible. Can you trust the system vs. should one be worried about having others take of advantage of your sharing? I think these posts are interesting in that they externalize a distinction between what some advocate and what they then are willing to do. We propose openness, but we also want to support ourselves doing something we value. Nothing wrong with hoping to make a living doing something you value.