Here's hoping it's in preparation for a 2nd season! The world needs more animated Kessoku Band!

Honestly anything with a non LTS release schedule will be fine. So long as you keep a relatively recent kernel and GPU drivers it pretty much doesn't matter. You can go for a rolling release like Arch or OpenSUSE Tumbleweed or a staged release like Fedora. Even Ubuntu or it's derivatives are fine so long as you stick to the yearly versions and don't have a particularly bleeding-edge hardware.
My only advice is stick to the popular stuff. This applies to both distros and desktop environments. Much easier to troubleshoot things and find help and they have more people using them, which usually means the experience is more polished and bugs get fixed faster.

I always respec Shadowheart into anything but Trickery domain, usually Light or Life. I also generally respec all companions just to fix their ability scores, some of them are terrible by default.

Cleric has a domain for basically everything in it, you can run a whole party of them and not suffer from the lack of any role.

I used it a whole 2 times in my entire playthrough. Once to get a certain book from it's trapped pressure plate by throwing it, another to help a certain dwarf from his predicament. The biggest thing that stops me from experimenting more with it is it's limitation to once per short rest and only being present for 10 turns. I get that it's for combat balancing purposes but it does make me just never bother summoning it. Wish they removed that limitation, gave it more utility uses and just completely disabled it's combat abilities instead.

Karlach is a simple gal, Duergar are bad slavers, Nere is bad Absolutist and also a slaver. Why side with either when you can chop both into pieces and kill two slaver birds with one greataxe!

If you don't care about the lives of the slaves trapped in with him then sure, you can consider it a win.

Using the open source driver with Nvidia is a bad idea, your card is locked at the minimum clock speed and it's general quality is not comparable to the proprietary driver (this is purely because of Nvidia's hostility to open source, not due to any inabilities of the developers of Nouvea.)
I'm gonna assume you are using the default desktop environment of Mint which is Cinnamon. Have you tried booting a different DE, or even better, a different distribution with something like Gnome or KDE to see if the issue persists?

How can DE always manage to take this game in the absolute fucking wildest possible direction and surprise everyone! I love it! When they teased Wally getting involved, never in a million years would I predict things going this way.
I love the way the stone Man In The Wall tileset looked and the weird creepy enemies shown there, hope we can play some actual missions in there and it won't be just for the quest.
The only thing I'm sad about is that I have to wait all the way to 2024 to see more of it.

I don't know why our poor shorty races are so under-represented, Larian did a fantastic job on their models! Compared to male elves and tieflings, the dwarf and gnome selection is vastly superior. And gnome racials are absolutely crazy, who wouldn't want advantage on all the most debilitating saves!?

I'm not happy that they still haven't figured out the "pick who initiates dialogue" problem. This has been a thing in Divinity: Original Sin 2, and continues to plague us into Baldur's Gate 3. It's really annoying to watch your party face Sorcerer or Bard sit in the background while the Barbarian gets to fumble all the dialogue checks with their 8 Charisma score just because they happened to be the first one to enter the room, or the one who was closest to the boss before they decided to plea for their life (looking at you, Hag...) There is also the dilemma of whether to pick the dialogue options you would pick or the ones the character speaking would. I would love to pet that puppy but Astarion happened to walk into the door first, so I guess I'll have to pick the option to kick it instead or break character.

At this point I'm more excited about community projects like Skyblivion, Skywind or Beyond Skyrim than the next official game with how long it's taking. Skyblivion is planned to release in 2025 and their new roadmap shows how close to the finish line they are.