Yes! Sorry, you're right. I must have lost it when creating the test survey. So it's added now and at least that seems to fix the gap between the +/- button and the skip button. Just the space after the skip button remaining.

Just the space after the skip button remaining

Which space?
 

Evenb here you can minimize spaces by changing the paddings.
Investigate with the webdevelopment tool to find the affected classes ("contgrol-slider-buttons" and "ls-answers")
 

Joffm