Pro tip almost all of those screens allow you to pull the bottom out to make it flat again. I don't think I've ever been on a flight this wasn't true on actually.

Honestly, if you fly coach, don't plan on using a laptop. There really isn't enough room for your elbows and there probably isn't enough room for the laptop itself unless you have a mini version of some kind. I'm not saying it's the way things should be but it's the realistic expectation in standard coach.

Don't most of these monitors swivel so that the monitor point is moot?

I've done all three of those things on a reclined seat. Why weren't you able to?

Different seats? I travel frequently and there are differences across airlines and also laptop sizes.