So no the toolbar is currently not customizable. It is on my list but require a lot of redesign and a total custom toolbar
Actually ... as the expression goes "When there is a will there is a way"
Attached is a screen capture showing my toolbars. Note that the icons on the file toolbar that I was not using have been blanked out.
For me, the reduction in visual clutter was worth the minor effort required to edit the icons file.
Also, for me the "C:/" on the clipboard icon was more confusing than helpful ... so I removed it.
The 5 black icons containing yellow text are my Quick Paths. Yes, I know I can get to them via the "star" icon, but I find I use these enough to justify having single click access. It's great that this toolbar is so customizable, since I like to use it for nearly everything. (I don't particularly care for the look of the button area at the bottom as well as the space it takes up, so I have disabled that.)
~Paul