The first point must be cross-over from angular :-) He said he doesn't like angular, that must be why.
Personally, I am super jealous of angular for having observables. I work with React and would love some Rx in our app too, but we aren't using it. Ditto for typescript - our app is mostly untyped javascript with sprinkles of Flow, while angular would have enforced typescript.
2) Please clarify what you mean by this.
3) By all accounts, the fiber codebase is much simpler than the stack codebase, performs similarly and opens up some exciting new possibilities.