it seems that in perhaps all of these passages... the lusting proceeds some kind of actioning.

It's not just desire alone... but desire to act on it that makes desire lust.

and it's in the going out and doing that acting that the real sin is to be found.

Even in the passages on lusting with the eyes or the heart there is still intent to do something beyond admire from a distance.... in my opinion.

Blessings
Cat.