Notice how the columns are too narrow and text is obscured. It is not possible to change the column size.
I propose that we either make this window bigger, and/or allow the user to size the window to whatever size they want and/or allow column resizing.
Are You talking about #25?
Those are two different issues. While the columns should be re-sizable the window itself could have better dimensions. A 3:2 view is mostly preferred.
Issue #55 - open customize.xul as a resizable window.
Also set it's dimensions to 3:2.