A toughy but a goody.
Unfortunately, like all approaches to communication, it's going to be individual to you, your supervisor, and the relationship between you two. But I appreciate that isn't too helpful - I DO have some principles that I hope will help.
Again, this is all individual to your situation. I hope it helps.
To try and answer your three questions:
"You get what you pitch for... and you are always pitching", Daniel Priestly.