What about removing all fixed icons in lister's border and replace them with custom buttons/icons when using a toolbar? The "hardcoded" icons could be left on inactive toolbar, and if a toolbar is used, they can be cusotmizable buttons to fit to the personal design (as already requested by users in the past). So everone would be pleased.
You can do that already (except for the close button, which is special); search for FDBBUTTONS in the release notes.