Comics Continuity Catastrophy
Unexplained are how Amy knew she would need a skin spell, the location of Warren during season 7, how this could possibly be consistent with The Killer In Me, and most importantly how the First Evil could appear as Warren if he never died. The entire continuity of season 7 dies unless there is some explanation on the last point.
Of course, just because Warren tells Willow that he never died doesn't mean he didn't. Maybe he did die and Amy reanimated him but lied and said it was a skinless survival spell so he would not worry about possible zombification side effects; in that case he would be telling the truth so far as he knows. Or it could mean that he is lying to Willow. Let's not take the exposition at face value when we can still hold out hope that Joss hasn't simply decided to take this new contempt for fans out in the open.
If there isn't a good explanation then, as speakr2customrs says, the issue of canon or non-canon status for the comics will be settled. Contradict bedrock established world rules and your fanfic comics cannot be canon no matter who endorses them.
In sororal matters, Dawn describes Willow as being like a mother to her. I recall Tara being like a mother to Dawn. I recall Buffy being like a distant, neglectful mother to Dawn. I recall Spike being like a mischievous uncle to Dawn. But Willow and Dawn never really bonded in the teevee series. And Dawn was holding a pretty big grudge over the activities of Wrecked and Two To Go through season 7. As we enter the comics we learn Willow has been gone for a long time. Just when did Dawn develop this view of Willow? Fans deserve more competent characterization than that.