"To say someTHING is shit is not aggression. To say someONE is shit, yeah."

You're splitting hairs here. This is the same as the difference between shouting at nobody and shouting at someone, or punching a wall and punching someone's face. An aggressive act doesn't necessarily need to have a person on the receiving end.

"Swear words have mutable connotation and nuance, a continuum of meaning, like all words."

No, not all words. If I say "orange", you know I probably mean the colour orange or the fruit. You know I probably don't mean blueberry.

Likewise, if I'm someone who doesn't normally say the word "fuck", you know when I say it I'm either referring to the sex act in a vulgar way or I am expressing some form of anger.

When people use swear words repeatedly in everyday speech, they are doing so to appear more aggressive and confident. But actually, in doing so, they weaken the word's power for them.

We need strong aggressive words that we reserve for when they are needed and don't use in everyday speech.

Like the word "cunt". If I never use that word, and then I suddenly call you a cunt, you know I am being aggressive towards you. But if I was someone who says that word all the time in normal speech, it would have no effect when I called you a cunt.