Questions about UniFi Protect G4 Dome

Yes, a very discreet red LED. I don't know if you can switch this off in the settings. Probably not.

Unfortunately, we currently have no information on when the item will be available and when we will be able to deliver it. As soon as something changes...

No, the mounting system has changed.
But it is still simple.

Hi. No, unfortunately not. It must be one that complies with this standard: 802.3af.
e.g. the one from Unifi: https://eu.store.ui.com/collections/unifi-accessories-poe-injectors/products/u-poe-af?_pos=1&_sid=d88c749a4&_ss=r...