Howdy! I actually had to go back in my code but it looks like the delete key will delete parts while you are holding the building tool. Simple press "e" when looking at the buttons to use them. You can link the outputs of the buttons to motors by using the tablet thing's instructions. I plan on redoing how all the control stuff is done when I get time but life has been in the way. I might try to make a video tutorial at some point but if I have the time I'd rather make everything more intuitive.