I'm not a dev but I can kinda predict what an answer would look like.

Sound is on the Rejected element list which you would have seen had you read How to suggest an element. Although the paragraph about sound does mention an element like NOTE, it wouldn't be a simple addition as there's nothing else in the game that emits sounds, and it's also mentioned in the paragraph that TPT is a particle simulator, not a DAW. Another thing the paragraph says is that it's hard to imagine how sounds would work. From a dev point of view, things that are hard to imagine are not yet worth to be implemented.

Turbines count as a kind of moving solid, something that's also on the Rejected element list. Moving solids are brought up from time to time but they're just too much pain in the neck, difficult to code and are generally out of place. *Personally* I think that a turbine would be out of place the same way in TPT. I also think that the different ways people come up with to build things that *look* like turbines add to the TPT feel.

The Gravity category (I guess that's what you mean) ... I'm not even sure. There *is* gravity in the game; there are PGRV/NGRV in Tools, you can generate gravity with GPMP, you have flying gravity sources called GRVT ... not sure what else you'd need.

Anyway, I don't see how any of these is easy to use :P

I still don't think I fully get what you mean. You want solids to act like powders in a user-defined area?

Oh yeah, that also counts as a movable solid. Anyway, I might have seen something that's similar to what you're suggesting, I can't recall who was behind it though, maybe jacob.