Regarding some of the state of The Empire thoughts;

I tend to err on the side of believing they didn't fall because an emperor and his counterpart were killed when one base was destroyed. That sort of thing has happened in real life plenty and the regimes and countries are still alive & well, as well as remaining a threat. Not uncommon on a single planet, certainly possible in a galaxy.

Have there been any theories in the nerdosphere of there being a twist where we're seeing a restructured Empire? Not so much a rebirth as a shift and restructuring to a more aggressive power?

What about the figure addressing the troopers being Leia? That's as crazy a theory as I've ever had, but it came to me while I was watching the trailer for the fifth time. (today) ;-)