You are.

: modes are exempt? what do you mean?

Sorry. That was suppose to read "Mods".

: I wanted to say the Structure category, but that's kind of obvious, isn't it?
: Without it you can't get anything done, at least you can't really build
: anything. I was kind of leaning towards the Natural category under
: structure, but IDK. You reminded me (in your next post) of the new
: specialized objective pieces, and I do think those are cool and useful. I
: feel like I'm forgetting something else... IDK... after thinking some
: more, I'm somewhat leaning towards all the thin Building block pieces,
: though.

Without them, a LOT of custom maps wouldn't exist. Especially since they are in large quantity and cheap.

: The simple, easy answer is Forge World, but I haven't tried to do a lot
: Forge-wise in Halo 4 (I've spent a bunch of time in Forge, but I haven't
: gotten much done), and most of my attempts at making things were on Forge
: Island, so I don't feel like I can totally fairly judge them like that...
: but Forging is also harder and less enjoyable in Halo 4, which
: automatically brings them down a certain degree.

The lack of fine turned movements is what makes it more difficult. Be glad it's not as it was in Halo3. ;)
I use the magnet system a lot more then I ever expected. Tough flawed, it has greatly increased map building. oth my new maps for Friday greatly benefited from it. Fine Tuning in Reach was mostly used for the same reason as magnets today. But now it's missed for map astectics reasons.

: 1. I'd like access to all the objects the developers use in making the game
: (at least the ones that show up in the game). This might not be that
: realistic because they're not left in object form in shipped maps (unless
: they're made using Forge), so they're not already there, and they're not
: that way because of how the maps are finalized, which has to do with the
: second issue: they can take up a lot of memory.

Not gonna happen. There are a LOT more developer tools used then you may realize.

: 2. I'd like to be able to apply any texture in the game to any object and to
: reorient it. Just being able to reorient textures could be really nice to
: have. It shouldn't be too hard to give us the ability to use any texture
: on any objects, but I'm not sure about reorienting them.

I can see that happening. 3D items tend to have a multiple texture layers. Including a layer for tileable textures wouldn't be difficult. Especially since those textures may already be in the game. A slider system with a compass wheel could make adjusting textures possible. This system would basically only cover the white areas of objects found in current Forge. Covering the entire object would be possible nor be practical. I like you feature suggestion. Certainly would help in blending objects together.

: 3. I'd like to be able to compile maps. This is how mapmaking is done on the
: PC and this is how the developers do it. Originally it meant making a
: collection of polygons from scratch in a design program, saving it as a
: file, running that through a special map compiling program, and then
: testing it with the engine. Nowadays developers use a lot of shortcuts and
: time-savers in putting together those polygons. I'd like something that
: deletes unviewable/unreachable polygons-- the visible component and the
: collision component-- and turns everything else into part of the map
: geometry. I'd also be fine with something that has us mark the polygons to
: be deleted. This would improve the performance of custom maps, it would
: affect file sizes, though I'm not sure in what way, and it would allow us
: to, as long as we build in stages, have an endless amount of material. You
: could place all the objects that are within the budget and other
: limitations, compile the map, continue building on the new map, and if you
: still can't make all of what you want, compile it again and go back to
: building. Of course at some point you would get performance issues still,
: but this could help a lot.

That's never going to happen. To many complications could arise from it. The most obvious would be giant penis bases, etc. For some sick reason, gamers always feel the need to place penises in games. But outside of that, there would be too many technical issues that could happen. Sounds more like you would like to be able to save a Forge structure/creation and bring it into another map. Don't see why that wouldn't be possible. Unless the used objects aren't in all maps.