-What I am thinking of now, there will be full boss tiles and possibly boss scripts, some bosses would be much harder to script in.
-There will definitely be proper Z3 mountains, although they may be slightly edited to be easier to use.
-There probably won't be Parallel Words graphics. Since ALTTP already has a ton of graphics, adding Parallel Worlds graphics would probably overload the tileset.
Regarding PW stuff... Not really? For the most part, it;s trees, bushes, some structural tiles, and Link's graphics. The canon shooting enemy was in the Z3 tileset, as were some other objects that PW used that Z3 did not. They were in the ROM, but never implemented. (I happen to love the PW trees and buildings, and we already have a near-complete PW tileset that could be used as a base, adding in tiles from Z3 that are missing...)
Bear in mind also, that we're hoping to expand the tile pages for 2.54+.
This sounds good though. If I had the time to make a full tileset, this would already be done.
I have quite a lot of Z3 object scripts that are each in one of the following states:
Done, working.
Probably done, untested.
Nearly done, needs some revision, and testing.
Partially implemented, spanning various files.
Sketched out, and wouldn't be too hard to implement.
This is mostly item, and engine related. I do not make many npc scripts, but on the plus side again, if we make this for the next ZC version, where it can be a scripted quest template, we might have some useful new things, such as shocking NPCs, ice rod/enemy freezing. lift objects, and similar.
Much of that is on my list, so some of the dependence on scripts could be minimised, and even in 2.54, I added in script flags for many of these effects, and enemy defence conditions that while unimplemented, can be read and be scripted to produce an effect, such as shocking Link.
Then, if they are later implemented in the engine, we need only remove the script for the effect.