OK Nick,
Just finished your own book on the Harry Potter books. First, I think she did a good job keeping Snape ambiguous in this book. I don't think we are any closer to knowing where his true allegiance lies (I suspect it is with himself). Yes, he killed Dumbledore (EVIL!), but he was under the binding of the Unbreakable Vow, in which he promised that if Draco for some reason could not fulfill his duties, that Snape would. He does let Harry off in this book when he could have killed him, as well as saving him in other books (Good), but he also says in Book 6 that Harry is the Dark Lord's to kill and that no one is to kill Harry but Voldemort. So, I am not sold one way or another with Snape. I think we will find him to act in his best interest at the time, which is why I like him as the double agent.
As far as adults go, I agree with you somewhat. I think that, in the end, Harry has to fight by himself, or with Ron, Hermoine, Neville, Luna and Ginny along, but I think that the story could be cool with adults fighting as side stories. For example, Lupin and George fighting Greyback or Tonks and Moody fighting side fights with key Death Eaters or Hagrid and Grawp going aginst the giants; things that need to be addressed, but not necessarily by Harry. I definately agree that Harry has to fight Voldemort without adult aid as well as Bert being a square. I would offer Fred and George as prime examples against Bert's stance of "hard work makes a good wizard" being just wrong. They didn't even finish their schooling and they are a pair of fantastic wizards. Even Hermoine comments on how their prank magic is actually briliant and we get the impression that they didn't do a solid day's worth of hard work while they were at Hogwarts (Quidditch aside). I think we've seen constantly throughout the books Harry's having some sort of natural instinct or luck that is, shall we say, enhanced for lack of a better word, by his friends. In the first book, Harry would never have made it to Quirrel if Ron and Hermoine hadn't been there, but he also manages to elude the advances of a possessed, fully trained wizard while being not only a first year student, but having only that year learned that magic existed. In the second book, he gets help from Dumbledore via Fawkes; in the third, Hermoine helps him save Sirius; the fourth Dobby, amongst others, helps him get through the triwizard tourney; the fifth he has Ron, Hermoine, Neville, Luna and Ginny (I think). The sixth ends with Ron and Hermoine vowing to be with him every step of the way. The whole series has Harry eeking out victories using some sort of natural ability combined with timely help from friends and a good deal of luck, not just hard work.
I'm gonna stop now as I don't want Nick to think I am competing with him in some sort of longest post contest. That could only end in hours of sitting here reading his verbose responses.