playerctl can list and control (most) media players individually, and would be suitable for writing a script with. In terms of rebinding keys you might be able to set them to run shell commands using global shortcuts in KDE system settings, although I’m not at my computer right now to test it.
Is one of your monitors HDR? I’ve been getting similar issues (EndevourOS) ever since upgrading to 555, where both of my monitors are black/no signal when logging into Wayland. Unplugging my primary monitor fixes the secondary monitor, and it seems like HDR is the problem in my case - https://bugs.kde.org/show_bug.cgi?id=488941
After deleting ~/.config/kwinoutputconfig.json, I could login. I did some tests and the issue happens when HDR is enabled. In the config file that put “highDynamicRange” and “wideColorGamut” to “true”. Just changing “highDynamicRange” to “false” doesn’t work, but if I put both to “false”, I can login again.
Simply deleting kwinoutputconfig didn’t fix the problem for me but I haven’t tried setting it as read-only yet (Probably a good idea to back it up first). My X11 is working normally so I’ll stick with that until this bug is resolved.
I had a similar issue with Overwatch, adding
LD_PRELOAD=""to the launch arguments fixed it. It seems like the issue I had is caused by a change in steam overlay for the new game recording feature, which happens even if the overlay and recording are disabled.https://github.com/ValveSoftware/steam-for-linux/issues/11446
https://github.com/doitsujin/dxvk/issues/4436#issuecomment-2466646597