Bravo, Craig, I enjoyed your rendition of Mad World.
Generally I think you are doing great. I especially noticed your hand kept moving in the couple of beats of silence before singing ‘mad world’. I think once or twice the left leg movement stuttered a bit. Not an issue, just keep at it.
In terms of getting familiar with gear, recording etc. I’d suggest that if you are not doing post-processing of the audio or blending backing then you could drop Reaper and just record directly in OBS once you’d done some sound-checking to get the levels as you want them.
I don’t know about DroidCam. I have used OBS Ninja to use my phone as a camera. It was free and worked like a charm, so maybe worth a look. Check it out here: Producing a video with phone cam and an audio interface
And your legs are just fine as is.
Look forward to the next!