Yeah, I don't like that this is the default, but "Firefox literally sends your keystrokes to Google" could easily be interpreted by many people to mean all of your keystrokes (not just the ones typed in the URL bar).

It would have been better to say "by default Firefox literally sends every keystroke you type in the URL bar to Google".

In my opinion it is a user-hostile "feature", and should be pointed out, but not in way that could be so wildly misinterpreted.

Which is how instant search works, right?

Describing the cost without explaining the why is really putting a spin on things.

It can also be disabled in preferences if you don't like that functionality.