Annoyance 2 - since you hear the "connect" tone when the AirPods connect to a device, my guess is the author's AirPods have connected to a device they are not looking at. This is what was happening to me before I realized the auto connection was configurable.
Annoyance 3 - this happens for my other Bluetooth headphones that have a microphone when using Mac OS as well. It's a Mac OS issue. I've noticed with a recent update that it happens less frequently. The fix is to set the audio output to the computer speakers, then back to the AirPods.
Annoyance 5 - yeah, switching takes time. Based on my experience with Bluetooth devices, I'm not sure how much this is AirPods specific. I ended up buying a pair of the Sony WH-1000XM4 headphones because they can connect to two Bluetooth devices. This solved the switching delay, with the caveat that the mic on the WH-1000XM4 is not great so I also bought a cheap USB mic for meetings.