There is another way as well by pressing F4(or was it F2?), it isn't nearly as optimal but it can be easier getting used to, especially if you're playing on a controller as FO, cast/caseal or do gear swaps(not just weapons) often.
I know how it feels to be disturbed by OCD, I have deleted multiple characters between lvl 150 and 170 because I wanted them on specific slots/cbanks, for now you can reorder and rename the cbanks at least but that requires you finding the file holding that info somewhere in the game's folder.