Snap does theoretically support other stores, but the code for the canonical store is proprietary so you’d have to reverse engineer a snap store and hope that canonical doesn’t break it with an update. Also apart from Ubuntu nobody uses snaps so why would anyone make a snap store? Btw they have improved snaps with faster start times and such, so they aren’t that much slower than packages or flatpak.
I have used a lot of different distros and I never had dependency problems whether on Linux mint, Debian, open suse or fedora. And yes, this can be a problem, especially on distros like Manjaro, but you still can use flatpaks/appimages/snaps and don’t deal with dependencies at all. NixOS and all rolling release distros can be great but they are not meant for people who are not ready to troubleshoot their system at any time. If you stick with a more stable distro like Debian you will most likely get a more reliable system then with windows.
Originally there was KHTML, developed by KDE for the konquerer browser. This was then forked by Apple to WebKit which is used by safari and gnome web. Google then forked WebKit to blink, the browser engine chromium uses.
SearXNG searches google, bing etc. for you and shows them to you. Speed depends on server speed and user number. Even if you don’t self host you can change the search providers in the settings, which can have an effect on result quality, but the less you choose the faster
I have tried all the engines for this post and Ekoru has been working fine. I’m using the Firefox rpm on Fedora, slightly hardened, no VPN, Quad9. Make sure the Ekoru extension is up to date and has all the necessary permissions or alternatively try lilo