[Angel Crawford]

First time, Calibre punches you with a lot of functions.
I needed a few days to realize, that you can customize everything you want with Calibre.

Go to "Configure calibre" => "Look and Feel" => "Main Interface" and change the Icons to an other theme.
On the same "Main Interface" Tab you can choose, if you only want to show Icons without Text and so on.
"Apply".

Now go to "Toolbars" => Choose "The Main Toolbar" and change Icons you want to see or not to see.

Greetz.