I'm no specialist, Nathan, but I'll chip in to get the ball rolling, awaiting correction as always from the better-informed!
1. Surely it would be seen as an original work - otherwise by reductio ad absurdum any work could be taken ultimately as merely as assembly of already-used words!
2. Surely use of quotation is covered by the 'fair use' provisions of the relevant international treaties, and is therefore not reliant on permission being granted?
3. In academic usage the Editor or Editor in Chief would be referred to as the progenitor of the work, although I have no clear knowledge about how the legal position applies - I believe in collective works of this kind the publishing house holds the copyright, and no individual normally asserts their rights as with, say, an imaginative creation.
I shall watch this space with interest!
