Good job so far!
1. I would like to have the option to move the X icon (close) of the panels to the left side of the window, especially when using the Dialog mode to run the game(mac users).
2. It would be great if you could utilize some Mackbook trackpad features to zoom in the layout view
3. The tab gradient colors need some work from the designer
EDIT: Also, when the game is being run in Dialog mode, it would be great to dock it in the editor like in Unity