This is the sort of question where Yoeman's Scale of Permanence comes into its own. Don't plant ANYTHING until you've managed your water, your access and your earthworks. Those three things are interconnected and it's the water that dictates how the other two are done.
This actually matters because if you plant before you do these things - you're extremely likely to have to either compromise your water management (you don't want to do that) or transplant some of your plantings (and why would you want to do that?).
Chop and drop of the existing trees - it might be part of doing the earthworks, building the hugel. It might happen when those trees are in full leaf (the chop and drop benefit is much greater when there are leaves, not just bare branches). Depends on where the trees are and what you need to do with them.
IMO, first priority items: Terrace, rain gardens, hugel, Paths (not on your list ;) )
Then: chop and drop anything left after doing the hugel that you want to chop and drop.
Then: Run birds.
Then: plant fruit trees, bushes, cover crops.
You're talking about doing a food forest, so you really want to be thinking in terms of your full seven layers and guild structures, not just bushes and trees. Ground covers, vines, herbaceous layer, root crops. Your space may not allow for a full over and under story development, so maybe your under story is bushes rather than under story trees, and your
canopy may be what normally would be under story trees. Nothing wrong with that. But you do want to be planning the guilds, with all of their elements, not just trees and bushes.
And the design and makeup of those guilds can tremendously change the entire notion of cover cropping. As in, you don't do it, because the guild IS the "cover crop", but it's also yielding for you and for the system. In theory well designed guilds are self-perpetuating and provide their own fertility needs.
You are also looking at getting quite a bit of work accomplished in a fairly small window of time. I don't know about your resources, it may be that this is well within your grasp ;) I know I wouldn't be able to get it done ;)