What reality warpers could defeat Sabrina? I think it's safe to say that Bruce Almighty, Q, Mr. Mxy, and others (possibly the Mask) could easily defeat her. But lower-level reality warpers, such as Beetlejuice and Freddy, don't appear to be on her level, if that list of abilities is true.
Would Sabrina have a problem with beings such as Thanos, Darkseid, or Juggernaut, etc.?
Well, Sailor Moon murderstomp her. But then again, Usagi has some crazy powers, so that really makes it unfair. I also think that Franklin Richards could beat her. Not sure about Zatanna and Scarlet Witch, though.
Sabrina stomps here.