I didn't find anything on Valve's issue tracker with a quick search, but maybe you'd like to investigate deeper.
https://github.com/ValveSoftware/steam-for-linux/issues?q=is%3Aissue+state%3Aopen
You could take a look at game's logs. For Windows titles, enable logs in Proton by adding PROTON_LOG=1 to launch properties, see README for details.
https://github.com/ValveSoftware/Proton/blob/proton_11.0/README.md#runtime-config-options
I would absolutely not want it to work as a controller outside Steam. In initial mode, aka lizard mode, it works as a keyboard and mouse because they want it to be able to boot your OS. That way you can even use it to manage your UEFI settings. Even in bluetooth mode, the og. SC works initially as a mouse. It's designed for HTPCs after all.
If unsure, go with ext4.
Another option is using libpurple compatible chat app, and using steam plugin for it. These haven't had much developement effort lately, but worked last time I tried them.
There is Plasma Bigscreen that's a modification for HTPCs. For touch screen based devices, a tiling WM is available for both Gnome and Plasma, though not baked in. IMHO bigger issue for both is a poorly working touch screen keyboard. This is something that SteamOS solves quite well.
My best guess is that you have an GPU that either doesn't support Vulkan, or has driver issues. But we shouldn't guess, that's what logs are for.
For Steam logs, running Steam from terminal as suggested is one way. Do note that error with wrong ELF class for game overlay library when starting any game is normal, since Steam tries to load both 32 and 64 for bit version for each game, and the wrong one will always fail. Arch wiki has more information.
https://wiki.archlinux.org/title/Steam/Troubleshooting#Debugging_Steam
For Proton logs, set environment variable PROTON_LOG=1. You can do it in Steam launch options, see Proton Readme for more info.
https://github.com/ValveSoftware/Proton?tab=readme-ov-file#runtime-config-options
With hardware and firmware issues system logs often point to right direction. Again Arch wiki has a good tutorial on it.
https://wiki.archlinux.org/title/Systemd/Journal#Filtering_output
Games often have their own logging too if you need to go there. You'll need to look those up, as they vary by game.
I hope this helps.
Regardsless what distro you end up with, do your research before bying new hardware. Any hardware, such as keyboard, usb bluetooth adapter or gaming audio headset might be unsupported or supported poorly, and require out-of-kernel drivers, firmware or propietary vendor software, that work only with some kernel versions or certain distros. There often are options that have great linux support and work with any distro, but you'll need to find them.
Pick your prefered update interval between LTS, 6 month point release or rolling based on how much time you have for administration. If you need you PC also for work, a rolling distro might break just when you need it the most. After choosing the update interval, pick the distro with chosen update interval you like the most. Say you know and like Debian but need a rolling distro, then Debian unstable might be a good choice for you. You can also run multiple distros and dual-boot.
Special purpose distros such as gaming distros can be a good choice, but they often have less developer resources and tend to die then the few developers lose their interest.
Regardless of your choice of distro, spend some time to configure regular backups.
Proton github has a possible workaround.
Here's my suggestion.
First, check your RAM with Memtest86+ or similiar tool. This is the first test because failing memory can and will corrupt your whole system, and it's easy to test.
Second, if RAM is fine, check the logs. This is more effective then just guessing. Just copy-pasting possible errors to your favorite search engine usually points to the right direction. Archwiki has a nice tutorials about logs.
Third option is to test components one-by-one. Remove all unnecessary components, such as extra SSDs/HDDs, wifi cards, USB devices and PCIe cards. If it doesn't help, test your CPU and GPU by running dedicated CPU and GPU benchmark tools. If you still get hangs, try with another PSU. If your components test fine, it's likely a driver issue. See Arch wiki article on Nvidia troubleshooting for some tips about that.
Your last option is pure guessing. It's the most time and money consuming way to debug with the smallest chance of success, but still many people prefer it. Most often issues like these are GPU issues, so it's a good guess. However it's still a guess.
I hope this helps.
Acording to SteamDB, there has been no updates. I didn't manually check all of the 355 depots though. I'd guess it's either shader cache, corrupted game files, or a bug in Steam.
There is also Kaldi, but it's not on F-Droid though.
It's quite common thing for keyboards, see this as an example.
https://github.com/denilsonsa/udev-joystick-blacklist