Yeah it’s long 
Well I think we should first be asking for all of the future maps to take advantage of the new forge. It would solve a lot of problems everyone already has easily. That all said I’m not completely against forge worlds. I just don’t want them to be the only maps to take advantage of this new forge we have. Though if a new one has at least twice as much content as forge world had then I might give it a break.
Anyway on to the suggestions.
I don’t particularly mind what the theme is, though I very much like snow. Anyway I think if it were possible to do, is to have themes changeable. Preferably including the skybox.
As for the forge palette. I think the basics need to be covered first. Which is to say we need basic forms of all shapes and sizes. This is assuming they would be predetermined for us to use. If they were to allow us to adjust the dimensions and size of objects then they wouldn’t need to make a bunch of sizes. Anyway to clarify basic shapes are boxes, spheres, cylinders, and cones. Just give us these in either a variety of sizes or give us the ability to adjust them and we can build anything, or most anything.
After that the textures need to be figured out. My problem with forge worlds object textures is that they don’t go together well or consistently. They don’t all flow from one to the other, if that makes more sense. Anyway like what has been suggested already have basic textures based on materials. This is the easiest way to do it. Especially if we are going to be able to edit the dimensions of objects. Also make sure to get more than one type of material in, or color of material.
That would pretty much cover everything, but lets cover the rest. The ideas above would solve the need for most if not all geometry. Still though, having options we currently have would still be good. The most important reason is for speed of forging. You could build a bridge out of blocks or you could just spawn one. Another thing it could do is add detail easily.
Changes I’d like to happen to the structure categories. The first being decorative, lets have more things to decorate with for one. I’d also like them to have a more flexible function. The next category would be the natural category. Pretty much anything to add to the lonely rocks is fine with me. I specifically want the terrain itself to be forge able though. I not only mean being able to add to the existing terrain but also be able to delete it all. The other categories I don’t have much of a problem with, as they serve their intended purpose well. The only thing I’d say needs changed is the need for corner pieces(diagonally cut squares) and curved pieces.
Giving us these options above would solve most all of our needs. For if we were able to delete everything then we could essentially, and literally build our own maps. I’m also certain it would lag less as well. Anyway they have two ways of allowing this. The one I think everyone would prefer is literally having the ability to delete everything. All that would be left is the skybox, and possibly a flat surface. On a side note if it is done this way let us determine the barriers. Meaning no permanent restricting, aside from the skybox I believe. The other way they have of doing this is to have the whole map act like how foundry was built. You could delete everything until there was a pocket of forging space. All maps should do this honestly, but we are talking forge world so I’ll shut up. The box should be either as big as the whole level, or less preferably it would have a bunch of smaller forging areas spread throughout.
I think that about covers it all, well the actual geometry problem anyway. Other stuff like fx, toys, and lights should be a universal thing for maps. This includes things like possible weather effects, or anything else that is added that others would like in other maps. This way you aren’t forced to and disappointed by the fact that you have to use a certain map to have say the rain effect.
This I feel is the way it should be done. While I do enjoy forge world I find myself disappointed by the fact that no other maps have the same potential. Again it doesn’t need to be just forge worlds that do this but I digress.