The only problematic thing i have had with airplay is samsung tv’s built in ones. It just keeps dropping but since i use it with apple tv 4k, it almost works like wired connection. Stablest screen mirroring experience i have ever had compared to anything.

And the resolution is much better on airplay while sharing the whole screen.

I usually buy a non branded somewhat good looking slim case and use it till its destroyed. It usually takes anywhere from 1 year to 1.5 till i replace it. My launch 11 pro has only seen 5 cases in its lifetime.

99% after 99 cycles is better than normal actually. Apple says 80% at 500 cycles is normal. There is 2 things it can say, normal and service. Unless it says service, everything is fine.