Concerning the crown, this is a component that is constantly in use. It may be defective (under warranty). If you're not sure, it would be a good idea to have it checked. As far as Bluetooth on the iPhone is concerned, it seems justified to me that the watch should try to reconnect itself to the iPhone. If the distance is too great or there's no Bluetooth, it seems to work in degraded mode. As soon as it reconnects, it will synchonise and resume its normal functions. I've also been told that you need to keep the Health application activated at all times. This is not the case on Android.

Hello
So with me the crown is bombproof, what I noticed with me the watch had two Bluetooth connections if you disconnect the Bluetooth connection on the watch only one connection remains and the battery suddenly lasts forever and you still get all the messages on the watch and I also use an iPhone. But leave Bluetooth activated there.

Funny, your question made me wiggle the crown on my watch. It actually has a little play. I've had the watch for a few weeks now and I would never have noticed it :D So I wouldn't describe it as annoying.