As for feeding the course piecemeal, I would give them the first module right after the order. After that, I would need more time to create the other sections. Truthfully I could probably crank out a new section every three days or so but I want to give myself a buffer to do quality work.
Generally speaking, does it hurt conversions if you tell the audience that a course will be released in sections on a weekly basis? If this is the case I may pursue a less ambitious offer as my downsell.