That's really annoying. He spits at it and stomps off.

It examines a parked delivery van and does not further bother anyone.

How many elementals are left on the human world, and how do people feel about trying to buy them?

There are a few hundred left (in captivity; wild number unknown)! Trying to buy them might make sense! Especially if they're better behaved than wild ones!

All the helpful ones so far have been freed captives, yeah.

Does Penumbra want to carry over a ton of salt.

Can do.

These people will trade salt for elementals!

Where did they get all that salt? Are they bandits? They sound foreign.

They got it from the ocean. They are foreign. They are not bandits.

How did they get all the salt here from the ocean without it being stolen by bandits?

A Shadow.

Why do they need more?

They sometimes want to make several trips in a short time instead of waiting for the Shadow to be back at capacity.

So they just want Shadows?

No, they also do other magic stuff and want other elementals.

Any kinds? Do they know there have been elemental-stealing bandits about?

Yeah, they have a plan to protect themselves from the elemental-stealing bandits.

What is it? People who have elementals would like to know.

It involves having lots of elementals, which is why they're buying them.

People who have or hope to accumulate many would still like to know.

They're gonna live on the moon.

Couldn't the bandits follow them with their stolen elementals?

Yes but the bandits would have to suspect they were there, and who would suspect that? Most people don't even know it's possible. 

If it's a secret why are they telling them?

These people are clearly nice and upstanding and not bandits.