Don't have to worry about recovery powers if you take them out.
Sure, but they're still worth Refresh, and still have Catches. Ghouls have no Toughness, only Recovery, but they're consistently described as very hard to kill.
We'll just have to disagree with this -- I don't see how "destructive force" doesn't mean, well, destroying things.
What I'm getting at is an attack where it just
doesn't matter if the person hit is wearing physical armor or not, and where merely physical resilience (Toughness) doesn't help.
Something like the Shardblades in Brandon Sanderson's Stormlight Archive series, that just phases through inanimate matter to cut life force directly, or the "brilliant energy" weapons D&D used to have, that harm living flesh but just ignore inanimate matter.
Or a petrification attack (Medusa, etc.)
Things like that, that are somewhat magical/metaphysical in nature and that physical armor shouldn't help against, but shouldn't be mental stress since they inflict physical-type consequences rather than mental-type ones. Being cut up with a Shardblade leaves someone with a deadened arm, not mental trauma.
That's good that it will be limited, but I still think the cleanest way is to ape the Swords' power and have it cost a fate point to use for a scene.
Then it wouldn't work for NPCs with negative refresh. Also, it's just
not that good.
Otherwise, what's to stop a player from deciding they're using that "particular mode of attack" for every attack?
Nothing. But it's still only a 2-shift conditional effect, so not unbalancing.
The only mechanical point of limiting it is so it doesn't get used with Evocation; that IMO might genuinely be unbalancing - if you've already invested in Refinement it would be better than spending more Refresh on Refinement.
But there isn't an equivalent of Refinement with its pyramid limitations for Fists/Guns/Weapons attacks.