> A huge learning curve is needed to understand OBS.
A big no. You can start streaming or recording with OBS within twenty minutes of installing it.
I did. Never used it before. I wanted a simple coding set-up where the whole screen is the main source and my webcam feed is in the corner as a box.
> Secondly, whenever I connect an external monitor to my primary laptop, the audio is not recorded.
Doesn't happen with me. Try restarting with the monitor added.
I use a condenser microphone, a Wacom graphics tablet (kudos to them for first class Linuc support), a webcam, an external monitor, and so on.
If you want to start streaming or recording within thirty mimutes of installing a SW, use OBS.