There's no way to get back to the forum listing without clicking 'Back' multiple times.
If you have deleted the special code, which puts the links there, in the header, you'll need to re-add the code. It is:
Wherever you put that, the links will show up.
The buttons do not work with the 'Dark' stylesheet, there should be a different set for them.
Dont' use the images then - to not use the images, just leave them blank. Actually, images are nothing to do with the stylesheets, and aren't even changed when you change a stylesheet.
Pinned topics should not say 'pinned' but have an image of some kind.
Actually, they should
say "pinned" - that's the way it was designed.
But, if you have a look around here, you will see:
Images instead of text (pinned, locked etc)
In the version notes for V1.2.6 at the bottom of the suggestions forum.