I think she should have had to reread her own stories between writing, as well as keeping them on hand for fact checking (to this day it bugs me that in SS we're told no witch or wizard who went bad wasn't in Slytherin, in POA we're told Sirius was considered the worst of Voldemort's followers, and yet apparently Sirius was a Gryffindor; I can fanwank an explanation for this plot hole but I would have liked a real one). Not just counting her piles of money and checking in with her outline that could have used a relook occasionally.

I think the crappiness of the canon romances helps with my HP zen too. Not only is it part of why I ship the couples I ship in the first place, and it keeps me from being confused about whether I have any draw to the canon pairs, it helps me feel better about it not happening because it could have been worse, it could have been canon.