Okay, so tell me what Hercules' Catch would be? Or Wolverine's?
Just saying 'this is stone, stone doesn't like vibrations' isn't cutting it. Especially if you are talking about supernaturally powered, magical constructs. They could have been enchanted so they are protected against vibrations, or they could just use a type of stone which isn't bothered by that at all, seeing as how there are hundreds of types of stone.
The T-1000 doesn't need a Catch for fire or cold. The extreme cold would freeze him, just as it would freeze the T-100, but the T-1000 just had a better way of recovering from that. Fire, also could melt him down, if applied for a long enough time, but as you saw in the movie, the steel bath didn't kill him outright, it just so much damage over such a long period of time, that it killed him. His Made of Metal aspect simply got compelled to say he couldn't escape from the bath. We're not talking about physics, but about game mechanics. Why isn't his Catch fire? Imagine you'd torch him with a flamethrower that was hot enough, for long enough and he'd melt. Yet, if you'd stop the flames, he'd simply regenerate. The only thing to fully destroy it would be to return his form to its base atoms: disintegration, which eventually happened as he melted and thus his molecules mixed with the steel bath.
I don't really see what problem there could be with a monster that doesn't have a Catch, why would such a monster be unbelievable? Something with Supernatural Toughness can still get terrible burned by fire, whether or not it is the Catch, they can still get Consequences relating to those attacks. If they have recovery powers, they just recover faster, for which they pay Refresh. Do you believe that Wizard's Constitution would need a Catch too? Normal humans can't recover from burns like Harry does, even if it takes time, so following your logic that humans are vulnerable to fire, Wizard's Constitution wouldn't work against that...