Once sharpened, they'll more or less stay that way; you'll still see some dulling, but not nearly on the scale that Johto usually operates at.

And he is welcome to distribute, but doing so will take up a considerable chunk of his time, and he'll basically be a sitting duck for the periods when he's focusing on getting the weapons cleaned up. So he may be able to make a couple of extras, but he won't be able to become a weapon-distributing dealer or factory, no.