Get ear trumpet for your volume mixer, for my needs at least it is better than the stock one anyhow

Family Link works okay for Android... It is google first party. Wish I could find something that worked for multiple platforms in the same app, but also that would probably be its own nightmare.

Try reseating your CPU, check the pins to make sure you didn't bend one. Taking some photos and zooming in can help you get a better look.

Got a parts list?

Did that happen to work for you?

Your monitor doesn't matter just let the computer run for a few minutes then turn the monitor back on