Nice game- some cool mechanics and concepts. Although I found the placing of things to be a bit senstive (at least in the browser)
Oh... For the first part, I know why. But, for the second, I don't.
For the first part, I made it so that if you click after you selected anywhere in the green area or the selection area, it won't be placed. That's so you don't place whenever you're selecting anything.
Thank you for giving me feedback!