Killing supply vehicles stops it dead just like any other rush.
No, it doesn't. What are you basing this on? I don't even use supply vehicles with my attack.
Also, I feel a point needs to be made here. Just because it's a "rush" doesn't mean I'm attack-moving directly into your base. My doctrine is to hit you extremely hard very early, aim to destroy your expansion and kill your cmd unit, and then I STOP and fill in the map behind me.
I don't actually have to drive into your base to beat you. Hell, I don't even have to fight to beat you. I just played against a guy who knew who I was and that I would be VTS1 rushing, so he made his base an unassailable fortress and waited for my units to show up. Except they never did, because once I realized what he was doing I just made a defensive line of my own right outside of his base and filled up the map behind me.
Even if I lose the same amount of points I kill, but still drive the enemy off of the map, I have WON because I have map control now.