SearXNG has maximum privacy and results, but it’s a bit too complicated for the average person. DuckDuckGo has worse results than google because of Bing base, Startpage is similar to DuckDuckGo, but it has as good results as google. Brave search has good results and is not reliant on other search engines.
Thorium is good for privacy and speed but not security, Vivaldi isn’t that private, ungoogled chromium removes everything google. Brave also has packages available for manual installation if you want to give it another try
It should work on Mint as well, but the theming may be off you will probably have to redo Icons and such. Just FYI, XFCE can totally look like Gnome (look at rhino Linux) if you theme it. You may consider installing the SaveDesktop app and redoing your XFCE setup (the unixporn community has some great inspiration)
It’s Not Bad, but against the malware that always is a step ahead it stands little of a chance as it can’t solve the “legacy” problems that keep windows from becoming more secure
The repo shows all the patches. It uses some patches from ungoogled chromium for privacy. It isn’t my recommendation here, I just mentioned it because Brave didn’t work for OP
No not really. Gnome for me is about 2.5 gigs of Ram, XFCE 700 megabytes and the CPU load also is way lower. XFCE can be heavy or light depending on how you configure it