I feel like there should be a grab tool in the game, if it isnt there already.
Can you elaborate on what you mean? If you mean a tool that letes you pick an element and use that in your brush, you can just press middle click over an element. If you don't mean that, do you mean something that can drag other elements around? you can do something similar with CTRL+X and CTRL+V.
To explain, its almost gonna be like the save tool, where you drag over a box over certain elements, only this time it will put the element(s) to the next place you click. For example, lets say you created a nuclear bomb, you can drag a box over it like the save button, then it has you click a certain area to place the bomb. I hope that increases your understanding.
This exists as cut-paste and stamps (ctl+x or s)
Thank you for letting me know