By default yes, but you can contact steam support and ask them to disable no violence mode for you. Usually takes less than three days.

I recommend startpage.com over duckduckgo. It provides at least the same privacy as DDG while having generally better results because it uses google's results instead of bing's.

Edit: The ultimate search engine though, as mentioned by macattack, is SearxNG because it combines privacy with every other search engine and even allows you to mix and match your result sources.