Can't comment on 2 and 3, but for 1... I'd say it's the opposite. I believe the Angular team took a long, hard look at what was working with React (and others) and that's why they decided to take their time to get Angular 2 right.

If anything, React-* is the stack that has a longevity problem from my point of view. Everything I do on the web I use React, and my impression is that even if I'm using a modern stack, everything breaks 6 months later because things have changed considerably. Many of the extensions React naturally need either fall out of fashion, or go through deep changes, or are just not that good. On every new project I assemble, I start from the assumption the architecture will be outdated very fast.

I hope Angular will make that kind of stuff a bit more solidified. We don't need a new store solution on every new project.