I find that reading fanfic has made my experience with this book much smoother. JKR's writing is on par with the decent-but-not-brilliant fanfic writers out there, and this is a very smooth work with close attention to canon and characterization.
I can happily and safely ignore anything I do not like about it, because my brain does not sort it as OMG CANON. It sorts it as "fic I'd recommend".
Spoilered discussion belongs in the comments here.