I had a quick play with it and its possible that I didn't spot how to stop it from happening but once I clicked on an object to draw I couldn't stop drawing.
Eg. I made a frame, scrollframe etc then clicked on button and made a button or two then when I tried to select one to move it around I couldn't, it just made another button parented to the one I had clicked on. I didn't test to see if pressing escape releases the drawing stamp but thought I would mention it just in case.
The way I code is a lot different but I will say from the code it generates it will definitely speed up my more complex addons.
As to Silverlight programming. I was wondering what that was all about, now I know