Heroic Launcher, Lutris, Bottles, or just launching them through the command line if you really want to for some reason, are your options. Heroic I just started using and it's great. It's especially good for games from other stores, but you can add anything to it. Lutris is pretty good, but you have to add everything manually (which you'll have to do no matter what for what you're asking about). Bottles is functional, but it is much harder to use than the others, but probably lighter weight if that matters to you at all (and I'll tell you now, it doesn't).

Unfortunately this is one of the cases where you're going to have to do some research.

Check ProtonDB to see how a game plays on Linux. I'm assuming the flight simulator would be problematic.

Usually the periferal drivers are built into the Linux kernel. Your keyboard and mice will just work, gamepads as well. Niche stuff like wheels and flight controllers will likely not work out of the box and you'll have to find a community based software to support it. Sucks.

If I were you I'd boot a virtual machine or a live USB drive and try it out. If you're not comfortable with the amount of compatibility just don't install it. Nothing lost

Currently, my favorite ways of running non-Steam games are the Heroic Games Launcher and Bottles. Heroic is especially nice if you have games from GOG or EGS. However, looking at ProtonDB, it seems that both DCS and Flight Sim 2024 don't work too well on Linux. Overall it sounds like it might be challenging for you to switch to Linux, but you can always give it a try and see how much works.

There are plenty of ways to run non-steam games and most games work out of box. Wine/Proton, the software that steam uses to translate windows calls to linux calls, can also be run outside of steam. Wine can also just run generic windows programs so config software will probably run fine.

The peripherals is where you may run into some issues as I'm not sure how well supported they would be on linux. I wouldn't know as I don't use any special peripherals.

Interesting, what year was that? Before Ubuntu shipped with pipewire by default I do remember it having the worst Bluetooth experience, so maybe something similar was the case with WiFi?

Anecdote as well: the non-working Bluetooth lead me to perform my very first (successful) dive into system files to replace Alsa with Pipewire

Except not really and about half the time there are breaking bugs that the average person cannot simply fix. Shit gets serious when a company like valve spends a load of programmers on this and gets it up to standard.

The comment above says they want to replace their W10 desktop, so it isn't what they want. If it's what you want then fine, but I was writing the comment for someone who wants a desktop, not a console. If you want a console, go ahead and wait or use Bazzite. If you want a desktop then the best options are already available and SteamOS isn't going to be it.

I've heard linux has problems with laptops with Nvidia cards, like I have. Is this still an issue? I'm getting pretty fucked off with windows but frankly don't have time to embark on an ongoing technical challenge.