Displacement is 1000nm, so 3 orders of magnitude less than 1mm. As for frequency response, looks like they tested up to 1000Hz. I see no reason why it wouldn't work at any frequency from 0Hz up to 1000Hz, and even higher. But because the displacement is so small you really need the higher frequencies to be able to sense the actuation.

That's just piezo's, you need to stack several layers to get a usual displacement. You do get high force, so they're typically used for high precision positioning.

I've been looking at piezo bimorph actuators as used in braille displays. Because they're cantilevered you're trading displacement for force (and size). That could perhaps be used to create a high resolution array with enough displacement at low frequency. Not really wearable like a glove, but certainly portable.