I can't see the text on any of the tabs except the active one. I would like to be able to read the text on all tabs it's too cryptic. Can I have white or grey tabs with black text?

AFAIK, the lack of separators can only be fixed by a userChrome.css file. See this answer: https://support.mozilla.org/en-US/questions/1346582#answer-1434487

Are you using a non-default theme as that can cause issues with the text readability ?

Can you attach a screenshot?

• https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem
• use a compressed image type like PNG or JPG to save the screenshot