How did you manage to go from evil dictator to plaguing everything in sight? I mean really plaguing the lands just makes them uninhabitable for the Horde and makes the Horde unable to obtain resources and soldiers, two things needed for the destruction of the Alliance. Until the Alliance is destroyed the Horde are pretty much safe from harm and that Sylvanas has an obligation to ensure that the Horde prospers so that its military prospers as well.
Sylvanas would plague everything in sight. Sylvanas is just as bad if not worse then Garrosh atm.
No Sylvanas would keep going and destroying everything. You act as if Sylvanas is a good person. She is not, she'll destroy every innocent person from the Alliance, even the children or brainwash them to grow up and turn into Forsaken whatever.