Eugenia
Ex-technologist, now an artist. My art: http://www.eugenialoli.com I’m also on PixelFed: https://mastodon.social/@EugeniaLoli@pixelfed.social
I use Linux since 1999 and I’m with you, I don’t like niche distros. I like them to be well supported with many devs in them, and a structure around them. My days of tinkering died already in 2002 (I’m looking at you Gentoo and sia). Since then, I want things to work the way I expect them. That’s why I now use Debian or Mint.
Video calls are not supported under Linux afaik, since they don’t enable it for the web version.
You need something like DamnSmallLinux, not Debian. Debian users about 800 MB of RAM with XFce, on a clean boot. It requires a minimum of 2 GB with a modern browser (one tab, 4+ GB with more tabs). DamnSmallLinux uses about 128 MB RAM on a clean boot, and with the Netfront browser about half a gig. Definitely better for such a laptop than any modern distro.
The tricky point to your needs is getting the app’s menu bar in the top bar. The rest are easy to do with almost all desktop environments. But getting the menu bar on the top bar, I think currently only KDE supports it (with a plugin), and MATE (with another plugin).
However, if you want the general feel of how MacOS 9/X feels, then Gnome with extensions would be your best bet. The rest feel more like simpler Windows, but in a mac skin. Gnome+extensions feel more accurately like a Mac, in terms of overall usability (even if the looks aren’t 100% there). So it depends what you’re after more: the feeling of using a mac, or the exact looks of it.
This looks like a hardware issue to me.
That’s fast enough to run the latest Linux Mint with Cinnamon. I have two laptops with the exact same cpu speed (passmark score) and 4 GB of ram. With 2 GB swap file you will be in business.