Hello , first i want to thank you for the work you are putting in the game!

So , we really need a Select and Move tool like the one in MS Paint.
Let say you make a Box , you could Select it and move it somewhere else. We already have the Copy-Paste by using Stamps , as you said Undo will come soon and this could be the next step.
This would help if you make something in parts and you want to see if each works before you can assemble them together.

Thanks and keep up the good work!