Snape's textbook and Narcissa's tears

[Ersatz Harry]

No: HPFGUIDX 133898

Two unrelated questions:

(1) I found it perplexing that Snape's old Potions text would make it
in the bin of old ones available for class use.  Perhaps Snape liked
to keep it close at hand when he was the Potions professor, but
something about its getting into Harry's hands feels a bit contrived.
 I can't imagine that Snape would inadvertently leave it lying around.

At the same time, I'm having trouble seeing how this little feat could
realistically have been engineered.  Was this the real reason that
Slughorn was brought back?  Let's see, says DD, Harry won't take
Potions any more if he got too low an OWL, therefore he won't have
bought the text, therefore my putting Slughorn in will get Harry to
take the class without a text and will create an excuse to put Snape's
old text in his hands.  Feels like a bit much.  Any thoughts?

(2) Way back in Chapter Two (Spinner's End), we have Narcissa Malfoy
demonstrating behavior most unlike that of the typical DE, displaying
what appears to have been real emotion -- love, we can say -- for son
Draco.  Will there be some parallel between Lily's love for Harry and
Narcissa's love for Draco that leads to a Draco redemption of some kind?

Ersatz Harry