Glad he's feeling better, the claw clipping will take about a week before he's got some sharps back. Fronts come back quicker than rears, he'll target your trees and furniture until he's happy his front paws are correctly pointy. He'll need to gnaw the back ones to get the husks off and reveal the fresh sharps underneath as they grow back.
The excessive biting and scratching was probably a combination of weird post-anaesthesia woosiness and the strange feeling of having no sharps. He would expect to feel his claws scratching his neck, instead there just rubbing (metacam+ soft claws). This is unusual for him and he may feel the world is a bit askew as a result.
I liken this the the feeling when you've just shaved/waxed your legs for the first time after the winter and that surreal "not mine" feeling you get when you put your jeans on afterwards - anyone get where I'm coming from here or is it just me?
Chubby had both canines out and now needs a flatter bowl shape to hoover up his food easily, try Jack with a side plate instead of his bowl and see if he's more comfortable eating off that.
My vet only clips claws if I ask him too but I know there is a train of thought that cats with mouth discomfort are liable to pawing and sratching their mouths which can introduce infection - perhaps your vet has decided it better to anticipate claw damage by clipping while sedated (or maybe he just does this as a "favour").
Did he charge for the claw clip, though? Mine ask about £7 if I request clipping as an "extra" to consultation. It's free if it's deemed part of the designated treatment.
