This is the one area which publishers have to insist on, because the marketing and bibliographic process starts long before the manuscript is finally delivered. They work in a spring and autumn marketing season. No 5 - attempting to avoid the anguish of watching someone going down a blind alley. No 6 - accept feedback, it is useful. The best approach is to get someone interested and enthusiastic about your idea, then shape the output with their guidance.
Education material is very topical so speed is necessary.
At Kogan Page, the process from final acceptance to publication is six months, five months to produce and one to market, review and sell. Library supplies work on an eight month time lag. The guidelines of the RAE acknowledge electronic publication. The essential element is that it must go through a process of review. There may be difficulties with permanence of electronic material.