Did you mias that (we can argue about whether that's intuitive) or does that plain not work for you? Scrolling back to the top should definitely be unnecessary..
Works just fine for me (typing on Android, in Aurora).
Doesn't work. AFAIK, there isn't a way to show the address bar unless you scroll all the way up to the top. I'm aware that Firefox on Android has the behaviour you mention.
Also, I haven't yet found a way to quickly scroll up to the top of a page.
Yep, seems to be missing here as well (2.1 prerelease). Sorry for speaking first, testing later.
It's another great example of how the Firefox developers have added in functionality that just makes the browsing experience less efficient or more confusing, without any real benefit. Getting a sliver more of screen space just isn't worth the inconvenience this "feature" brings, especially on larger mobile devices.
Disabling it via 'Settings' -> 'Display' -> 'Scroll title bar' was the first thing I had to do when trying out Firefox on Android, and that was just to bring it up to a minimal level of usability.