13) The header of 'library explorer' and 'track information' panel goes 1 pixel too far up, above the border. Would love a setting to adjust that so the border splits perfect between the two panels.
14) There is a line between the Library explorer header and the tabs. The colour comes from the left panel bg. I think the tabs should be moved 1 px up to remove it (or a setting to enable it).
15) The scroll bars in the left and right panel are offset 1-2 pixels from the headers. I think it looks much better if they go all the way up/down, like they do in the library. Maybe make it a margin setting so skinners can choose how they like it.
16) Adding to my request (3): I think the tabs look great like they do in the preferences and edit windows (look under). Would be a nice addition to the main window (in the 4 places with tabs). The border does not show under the active tab, but goes around it and under the inactive tabs (Similar to Firefox and Chrome). Also, rounded corners look better (not currently rounded in library explorer and track information).