The upper surfaces have been the subject of the attacks. Lots of separate little areas of damage.
This is the underside of the leaf seen above. No damage. And definitely no leaf-miners inside the leaf. The dark area near my thumb is simply the damage on the upper surface making the leaf look thin.
The big hole in this next leaf is clearly caterpillar damage, so I'm not worried by that, but its the white scarring that concerns me.
I looked very closely at this plant as I took the photos, but I couldn't see any creatures on it. So what do you think this is?