Respect should not be given thoughtlessly... nor should it be denied lightly either.
The way I see it, respect is an enabling, empowering attitude, an emotional resource even, and one that is expected to be given as often as it is received.
Above all, it is an odd form of resource that we pay for as we give it away. To give someone respect is to sacrifice a bit of our spontaneousness in the hope that it will put the other party that much more at ease. That is a good thing, but only sustainable if there is adequate retribution.
Proper etiquette, as I understand it, involves giving a measure of respect towards people one does not know well, and paying attention both to signs that it is not earned and that it is no longer necessary to extend it quite as consciously.
When a relationship is sufficiently self-nurturing, respect becomes a natural, even unconscious part of its expression. That is a joyous state that we all should savor, but it can't always be attained.
An often overlooked fact is that denying respect is at least as powerful an attitude as offering it, and arguably more necessary when destructive behavior is clearly acknowledged. But it is also a very serious and risky action, not truly reversible.