At the moment is the only way to stop a rendering, to close the gui (as far as I know). Not very smart.
Also an overall more powerfull gui with more options would be nice.

For example a build in text editor and an array (probably best an own window, activated from the menu, like in most of other programs) for preferences with all possible options in a clearly arranged manner.
Of cource this is all just my wishful thinking but i really mean, this would be great improvements!
