Oh, you have no idea how lacking in detail this is...
I took Dusk's suggestion of trying to get as much area in as possible and I think even my plans there have over-stepped the allotted time. I reckon with another couple of full days work I could finish the areas up properly (although probably not to the standard of what we already have), so if nobody has any objections (or beats me to it) I'll use that Phase 2 slot I've got booked (9th-10th June) to do exactly that. It's quite an early one, I believe, so that should work nicely. As it is I'm currently finishing a Disneyland-style castle and will then have a crack at getting in the absolute bare minimum to progress onto Xaser's area and give him an obvious line to develop from.
This will need a lot more detail, gameplay and tidying up when I hand this in (in about 4 hours) so sorry about that team! Like I say, I'll be more than happy to dedicate another two full days to sorting this out properly with my Phase 2 slot.
EDIT: Here's the aforementioned Disneyland - rather a lot of 3D floors go into this:
Now I'm on to bare-minimum stuff for the north-easternmost fire/brimstone area (storing the red skull key) and I'll just chuck a yellow skull switch into the completely undeveloped wing of the southern development so that it's functionally complete. Then I just need to do the join for Xaser's part and we're merely horribly disappointed rather than completely inconvenienced.