Sorry to hear it. I’m a casual player and the Linux performance worked well for me. If playing CS competitively, the little difference in performance is crucial.

Not sure what kind of multi player game you prefer. Dota 2 and CS have perfect Linux support and it may worth a try

I’m neutral with it.

A meta-search engine is a search tool that sends user queries to selected search engines and returns the result

I don’t know the cost of Waterfox to send the queries to the search engine providers. I’m afraid that the ad income can’t cover the cost