Yes, you're right, Snape is the ONLY fully realized Slytherin. Which makes him harder to write because there definitely is a "canon" Snape. I think that Draco is so poorly drawn that you can pretty much make up a whole bunch of shit and whose is to say it's NOT canon. My dream is to write a book in that DH year from Draco's POV. Sort of do a "Lestat" to Harry's "Louis."
I am continuously surprised by the reaction to HFN. I thought taking them out of England and cutting off their magic was a sure fire recipe for disaster, but I purposefully wanted them removed from Hogwarts and, yes, even, England because I think Hogwarts is a character and sometimes distracts from the "real" characters. I wanted to see if I could write them as "them" without ANY distractions, including the magic.
And, um, I worked with a bunch of guys like Juan when I was cooking. And there is not just a little wish fulfillment going on. I would LOVE to own a diner where I determined the menu and no one could give me shit about what I served.