Point number 1 is kinda implemented, as you are prompted when you first install an extension.
Point 2 is nice to have, but very difficult in reality. It would be pretty much unable to monitor every single extension, and self-made extensions, or extensions installed from files would automatically be exempt.
Point 3 is definitely a feature that should be added, as logging what an extension is doing makes sure that the user can know exactly what data is collected and where its being sent to.