I think left-clicking where you can see your gold (Sorry, dunno what it's called) to open the shop is a bad idea. I constantly click that by mistake while playing and have a shop pop up in my face.
Also removing when you drop an item on that window, you sell it. I just lost a ton of gold in my last game because I accidentally dragged my items half an inch away from where I wanted them.
Or maybe make it an option? That little thing really bothers me.