I think it all depends on your PC usage and if you have money to pay for an AV.
- If you only browse the Internet, I suggest you get an AV browser extension/add-on + an adblocker.
- Disable unnecessary permissions (specially notifications!).
- Change your DNS to another that protects from malware (Cloudflare and Adguard have a special DNS for this).
- Always delete cookies on exit.
- If you frequently download files, you can scan them with VirusTotal and ClamAV.
- When you want to execute a program you don’t fully trust, a VM or Firejail will let you run it without harming your real machine (good idea if you fear getting a RAT through WINE).
I learned all of this using Windows, and you can adapt it to any OS. All of my recommendations are meant exclusively for security, keep in mind that some of them are not the best for privacy.
But the only way to get full and annoying real time protection with all the typical antivirus tools on Linux, is paying an AV subscription. Most AV suites for Linux are developed for servers, I’m not sure if an active plan for home users exists. Just remember, it all depends on your PC usage.
I used Qwant years ago, but don’t remember why I stopped. Maybe they introduced ads like Google, or something more annoying. But it’s not 100% european, they use Google and Bing engines (just like most private search engines) to show you results. Also, there are some articles talking about how sketchy it really is (French government public funding, links with Chinese companies, and more).
About Vivaldi, it depends on your devices. In my experience, Vivaldi for Android works fine on weak hardware, faster than Brave and Firefox, but slower than Chrome. Using it on PC always was a headache, it’s the worst optimized browser I’ve used. They care more about productivity features than performance or privacy. It can feel bloated.
I understand your concerns about headquarters and privacy. I think the strongest european options for browsing and searching are Vivaldi and Qwant, but remember to try them before switching.