As one hopes at least some of the people working on this would have. Not that a degree confers magical powers, but any CS education will go over what's known to be impossible.
 ... by static checks via type system, termination checker and restricting access to "unsafe" modules/libraries. Of course it's doubtful how many extension authors would be able/willing to write their extensions in e.g. Idris.
I suddenly understand why Firefox isn't the dominant browser anymore. Mozilla hasn't adapted to being the competition. At all. They've, like, spazzed out and are pitifully flailing their arms around as they die. Not a particularly endearing way to go.
What a strange new world we now live in. Blink is now the future of the Web, Webkit is where you'll find occasional snippets of "oh, cute" when OS X updates, EdgeHTML takes over from Presto as the leading closed-source competitor, and Vivaldi trails everyone else as a source of "wat."
I wonder where Cargo will end up. It's a pretty weird sprawling mass as it is right now.
For anyone out there interested in the browser scene (and non-bureaucratic, non-toxic development environments!), I definitely have to recommend http://netsurf-browser.org/ - checking the site, I see they just got a JS engine properly integrated, and it looks like they've finally started major work getting the rendering engine up to scratch to handle dynamic page changes (once the page was in the canvas it used to be unmodifiable).