Microsoft and Facebook are also hiring developers to work on Rust. Google, Apple, and many other big companies use Rust as well, and I wouldn't be surprised if they do the same.
This is very good imo. Rust needs dedicated developers that get paid for their work. And with the upcoming Rust Foundation it feels like Rust is about to really take off to the next level.
There's a lot of inertia at Google with regards to Rust. Things are happening slowly there, but they're happening. I'm sure it'll be more public soon, but they didn't miss out on the Rust-grab after Mozilla let the project go, even if they haven't been as public about it.
The fact that both Microsoft and Amazon, Google's major competitors, are investing in Rust means that Google would be quite foolish to not be looking as well.
To a lesser extent so far, yes. As you mentioned there's the Fuchsia stuff, and some other smaller open source repositories. But there's also other areas, for example Android.
This is very good imo. Rust needs dedicated developers that get paid for their work. And with the upcoming Rust Foundation it feels like Rust is about to really take off to the next level.