I think what would also be cool is if you could create "low gravity zones". these would act like the center room in condemmed or outside ancor 9. you could adjust the strength and size of the zone.
What would also be cool is if instead of a list of blocks or platforms, we could make our own. there could be a H, W, and L option. that would really help.
Also the glue feature. i have created many maps where after i finish i look at it and think, 'this map doesnt fit here,' or 'i wish i could move this map some where else'. this would be an amazing feature/
What would be amazing though would be a carve feature. wouldn't it be awesome to carve a tunnel through a mountain, or create a massive underground hangar, or even create an entire map under ground. this would be amazing.
Also... Weather and terrain. what if instead or filters you could just enter a custom setting. like: Precipitation, Time, Wind, Temperature, and so on. this would be awesome. But wait. There's more. what if we had more natural peices. like: Rocks, Trees, Bushes, water, and grass. this would be AWESOME!!!
Also an undo button. i have acsidintaly deleated intire structures because i thought i didnt need them. i would love just to undo it.
I hope 343i reads this and all the other great sugestions.