I am looking forward to have all the basic and advanced functionalities in OBS binded directly to the board - for example changing scene, muting mic, starting/stopping a recording, mutting/displaing particular sources and so on.
Do these have shortcuts within OBS? (i'm not familiar with OBS other than what the program is used for) Most programs have a TON of shortcuts built into the app which makes simple scripting/automating actions really easy. If they DO have shortcuts, then it's dead simple. just make a macro with that shortcut on the keyboard. When you're in that program and hit that key it will output the desired shortcut. Now, this would NOT be application specific (would not call up OBS & do the requested action. It would just output the key sequence. You'd have to be in the program for the shortcut to work)
Let's use "save" as an example (control + s), make this a macro in the keyboard firmware with this key combination. then, whatever app you're in, when you hit that key, it will send that key combination and "save" whatever you are working on.
Volume controls are built into both QMK & TMK keyboard firmwares, as well as some other
media commands.
As far as changing audio outputs... that would have to be a script run on the computer. Did a quick search and
here's an example i found. Should help with some of the other scripting/automating you're looking to do.
Most of these media controls like the stream deck or other media control consoles have an app that watches for output from that device and in turn runs the needed script on the computer. (it's not actually the console sending the command, it's the control panel for the console that runs in the background on the computer that sends/runs these more advanced scripts/functions)
Look into what scripting/automation apps are available for your OS.
Make a list of the actions you want to do and see if there are any corresponding shortcuts within the apps to do so. Then we can see what can be done with simple shortcuts and what would need scripted.
Hope this helps.