I've been thinking for a long time about a way to move elements without super complicated methods or simply deleting a pixel of a substance, then placing a new one (even of the same type), but with a different particle ID. I've also noticed how PGRV moves elements, but at the cost of destroying nearby and moving other elements I did not want to affect upon using PGRV (the same applies to VAC). I then thought that "HAND" could be implemented as a tool which could simply pick up moveable particles and place them down upon releasing LEFT CLICK (and upon having held down 'LEFT CLICK', prior). Simply increase or decrease cursor size to move more or less moveable particles in-screen, or press TAB to move said particles inside of the corresponding shape of the cursor. In contrast to simply cutting and pasting, you can only cut in rectangles, and it removes solid objects and copies pressure blobs in the area in which the cut occured.
Read carefully; I said that "HAND" moves moveable objects and went on to say that cutting and pasting includes solid objects on screen. What I meant was that things that are otherwise subject to movement under pressure or gravity, like powders, liquids and gases could be moved by "HAND" exclusively, whereas cutting and pasting affects everything which is being cut, including solids (i.e. if you wanted to move SAND and CNCT for a city build, but BRCK is in the way, you can use 'HAND' to theoretically move them around the BRCK to another place). And, as I've said before, you can seemlessly move objects within a certain area with only the shape your cursor is in, so the particles would take the respective size and shape of your cursor as you move them.
For example, if I wanted to move some DUST parts., but only wanted to move 81 out of the 29596 DUST parts. on screen, I could scroll up from 1x1 to 11x11 and take 81 DUST parts. from the remaining pile of particles with either a trianle-shaped cursor, a square-shaped cursor, or a circular-shaped cursor using "HAND."
MORE: That is a possibility to add that. I just thought that "HAND" might be more seemless because of the preset properties (like triangle, square, and circle cursors moving particles, or particles get immediately placed one left-click is released), but that idea is also very plausible. Also, after copying or cutting, once you paste something the game will pause, depending on if you had the game paused when copying or cutting.