I really love cards in Azorius that return your own permanents to hand and even reward you for it.
I love the design of Tameshi to tie that theme which fits to og Moonfolks in with the new Moonfolk theme of artifacts.

When or if the "return to your own hand" as a bigger theme in a product? (icluding jump start, commander and standard)

It’s a theme we do on occasion, usually as part of a draft archetype.

With Omenpaths existing, is it possible to have a set with Satyrs, Aetherborn, Myr, Inkling, Demigod, Moonfolk, etc?

It makes such a thing possible.

mark please I NEED to know if we'll be getting more rabbits the creature type deserves more love i don't just want to stick every changeling in a morophon deck or use moonfolk i need bunnies or i'll die please mark

I’ll see what I can do.

Rabbits wouldn't be Blue? They're famous in mythology as trickster characters and in many cultures are associated with the moon which has obvious ties to the tides and with scholarship. Kamigawa's moonfolk embody that association, being based on the moon rabbit with their long ears.

If we played up that aspect, they could be blue, but that’s a little more bunny people than bunny rabbits.

Where are samurai, ninjas, and moonfolk on the beeble scale, particularly outside of kamigawa?

It’s tricky. They have to be in a world where those concepts feel at home.

mark, can i expect a lot of moonfolk?

It depends how you define “a lot”. I’d used the term “a bunch”.

Will we see the original races of Kamigawa in neon dynasty? the kitsune, moonfolk and orochi?

I would look at other returns to see how we handle creature types on planes.

Would the creative team ever consider having an in-story event that changed what creature types were available to R&D? I.E., would they ever be willing to wipe out the Kor or the Elves or the Moonfolk, etc?

That would significantly more people sad than happy, especially if the tribe has tribal cards (the theme, not the card type).

What are the chances we could see Moonfolk (besides Tamiyo) on a plane other than Kamigawa? Like how we saw the Kor again on Zendikar?

Kor are a bad example. Their home plane was Zendikar and some of them were kidnapped and taken to Rath. There are a lot of examples though of races appearing on multiple planes. Moonfolk are tricky as they aren’t quite as well known of a creature (outside of Japan), but if the right world came along.

Mark, you said an eventual return of Moonfolk wouldn't necessarily be tied to the "return a land to your hand" mechanic. But would them be tied to the "have many cards in hand" theme from Saviors of Kamigawa?

Probably not.