In Firefox, one must use 'ALT [F]' then 'r'
Reset everything.
I have a premium membership (formerly diamond), but I did not need to get the toolbar, so I never did. The two do not mandatorily go together.
My experience with almost all toolbars has been very bad, for the reasons you gave. The drawbacks to toolbars are not unique to Chess.com.
If you are experiencing technical difficulties, please notify the staff directly. They will help you.
The conduit toolbar used for the Chess.com toolbar will hijack your browser.
Even after removing from Firefox it will continue to hijack your home page, your default search from address bar, and several other features. Deleting all the entries it leaves in about:config in Firefox takes forever, and a lot of research is required to know how to replace them.
I feel taken advantage of because I paid for a $99 membership and got adware. This stinks.