Thanks for the examples.
For a next version I can add:
[]Clicking ones onto the canvas when creating a rectangle would open up a dialog which let’s you set size, pivot and position
[]A translate field which would always display and let you adjust the x/y position of the shape measured by it’s pivot
[*]Editable X/Y positions for individual keys
Snapping would be great and renderpick should help with that. camSchnappr uses that approach - I’ll see if I can implement it in Kantan as well.
I also like the edit field in Sketchup which lets you always enter an specific amount of transformation, be it when translating, rotating, scaling or creating copies. As these can work as offsets, this would simplify the way you create and place multiples of the same shape without having to do much math.
If you don’t want to wait for me to implement all of this, feel free to dive in 
Thanks again for all your input - this is greatly valuable.
Cheers
Markus