I was thinking more on the mobile app steam link ;) But i also have the steam link box in the living room. With a usb hub, and 4 controllers. They are still working as expected, but i usually play steam games.

Steam link fpr the win. You can play your pc games on the loo as well!

Price parity with other store fronts is only for steam keys tho? Right? I think the publisher can charge whatever on the other store front if they use the other storefronts infra.
It is just when you in effect sells steam infra, (steam carry the cost) you have to have the same price on steam.

Can run most windows games via proton atleast.

But then you are running windows…