I don't think Morrison will kill off Talia. Most of the speculation has been this is Morrison restoring things prior to when he first started his run. Talia will be dealt with...but she won't be killed off. Also don't have a problem with Talia killing the Heretic. A very Al Ghul thing to do...especially this version of Talia as you mentioned. I will say though I could see Morrison severely wound Talia. I loved that cliffhanger.
As for the mysterious woman in charge of Spyral...second time I think that organization has been mentioned in the series. Perhaps it is connected to a Kane. Otherwise I have no idea either.