And somebody's bites infect people with rot and they die, but I am still not certain it was explained in-book that it was the zombies or the rotting vampires
I'm assuming that's the rotting vamps, since that's the an ability they already had in pre-existing canon ("corruption")

I know the rotting vampires bite the zombies and the zombies become infected with...something... and want to eat people....Also I'm still really confused about how the infected dead rise as flesh-eating zombies, which I think is what happens in the morgue?

...yeah, I've got nothing here, sorry DX