By putting several different entries on the same "day", and then producing a special "day style" I managed to get something like what I was looking for. The unregistered public-at-large sees only the entry that represents the chapter. The people who I have friended as "editors" see the entries where I talk about my concerns and how to improve the story. People I friend as "teachers" see the entries that constitute the teacher's guide with questions/etc.
It's a nuisance to go through and properly backdate all the entries to get this effect, but that's stuff that could be taken care of with a hacked front-end. But once the information is in this form, it's very pleasant to work with, and the ability to instantly incorporate feedback from editors is invaluable. There are many more possibilities if this were done as a community such that teachers could then post entries that were private to the people they had friended as "students", carrying the assignments and help for that (with screened comments, presumably). There's also probably a CafePress-type market for pumping out print copies of work that has been put into a standard form like this.
I've spoken some about the concept of a collaborative storytelling database and this is a potential step towards that goal. Just thought I'd throw this out there to those who would like to see LJ-everywhere...