Again: let’s wait for some proof.

There might never be proof of who did it, but that hasn’t stopped you from speculating:

There’s still the possibility that Russia can use this as a leverage. “Sure, we will fix the pipes if you ease up with the sanctions” etc.

🤦

Assuming the damage is even reparable (which it sounds like it might not be) how would that leverage be better than the leverage they had, where they controlled the supply to four functioning pipes?