You want to talk about filler? Go rip a good few hundred pages out of OotP while you're at it, but don't touch my Hallows.
Sure, some of the tent stuff dragged, but the Hallows had everything to do with the story. It's what Voldy is doing like the ENTIRE time. in the story. I think it's funny because when Deathly Hallows was translated in Objects of Death, everyone thought it was a Horcrux reference, but it actually was the objects of death...anyways. I think Deathly Hallows had as much significance as the rest of the titles had for their respective books.
As for Hedwig, I see this death as a necessary way to remove a problematic character. At the point where they are constantly moving and the Death Eaters control the Ministry, having Hedwig around no longer has a point. It'd only function for her to be able to describe the "solitary hoot of the snowy owl broke the tense silence in the tent." She wouldn't exactly be able to fulfill her prior function in the books, of delivering letters and such. On top of that, it wasn't like Hedwig was specifically targeted by the Death Eaters. THAT would have been a little much.
As for happy endings, this is how I feel: Even if she'd killed off practically everyone, an ending in which Voldemort died would be loads better than an ending in which he lived, especially because we know that Harry would HAVE to be the one to kill Voldemort in the end.
I covered this in the other thread, but I understand your frustration about not knowing more about the fates of other characters, but I understand Rowling's motives here. First and foremost, you are going to disappoint someone, so shoot for what has the best probability. While little Shane in Oklahoma or Timmy in Rhode Island might wonder what happened to Hagrid or Grawp and whether Aberforth ever went on to do anything of mention, spending time on those specific characters would be problematic because they don't have wide appeal to everyone. Furthermore, it would be even more problematic to just bite the bullet and talk about all of the characters because there are HUNDREDS. I could probably list all of the characters that I wonder what happened to, but at the point where I do, I would be looking at a list with at least a hundred names. I think what happened is the RUMOR got out that JK was going to give EVERY surviving character their own little epilogue and then people assumed that that is what would happen. By focusing on Harry/Ginny, Ron/Hermione, Draco, and Neville, Rowling captures a lot of the "main" characters of the book. Furthermore, this allows her an AWFUL lot of wiggle room to come back and write more about the next generation of Hogwarts. Frankly, I'd take THAT over the cold finality that such a detailed epilogue would bring.
I totally agree with you about the Aslan comment. I made it in the spoiler thread because I thought a lot about that when it happened, especially because of the desecration of the body after he was "dead."
As for Malfoy's parents, while a good question, I think there are a lot of other characters that I would be wondering about. For example, I'm curious about the 50 some people that died for Harry. Who were they? With all of the name dropping in the series, I assure you there would be loads of secondary characters dead.
As for the wand ownership stuff, what exactly are you confused about? I found the wandlore absolutely magnificent and engaging, even if it was as much of a distraction for me as the Deathly Hallows were for Harry.
As for Voldy's death, it's quite poetic and ironic if you ask me. But before we get there, personally I would have preferred for him to be run through with the sword of Godric Gryffindor, but that's just me. Anyways, his death, although sort of anticlimatic, is quite ironic and poetic. Harry never, ever has to use dark magic or an unforgivable curse to kill Voldemort. He never even has to do a proper spell. The only spell he does do is the "Expelliarmus" disarming spell. Purely defensive, yet, according to Lupin, a signature move that wouldn't do anything against the Dark Lord. It's also very ironic that what Voldemort thought would be his greatest weapon, the one to finally kill Harry Potter, ended up being his undoing because it wasn't his. Arguably the most important aspect of how he died, however, is the fact that Harry even offered Voldemort a way out. He asked him to try for some remorse. The typical hero. Anti-climatic? Yeah. Cliche? Sort of. Brilliant, given the alternatives? I sure as heck think so.
Back very briefly onto the happy ending part, as much of a cop-out as this sounds, Harry's deserved it. Before the poor child has even turned 17, his parents died for him, his godfather died, an acquaintance died, and his greatest mentor died too. Add to that that in the 7th book, Harry has loads of people and things maimed and killed because of him. After all of the torment and hell that JK's subjected him to in the series, would you honestly expect or even feel it justified to kill off one of his closest friends or even him in the end? That would be all sorts of low, and for what? To not be predictable? To rebel against conventions and close off the greatest literary series of my generation on a sour note? What purpose would a sad ending have served? Or even a bittersweet one for that matter (although it's pretty bittersweet if you ask me, Harry has to deal with the deaths that happened because of him)? The ending made me happy because it gave Harry what he had ALWAYS longed for, a family and a normal life (ie, his children ask what the people on the train are staring at because they don't know the significance of their father to the wizarding world....awwww). As the series progressed, he started to have a sense of family and time after time, it was ripped from him. Finally, he gets it.
Technically speaking, her resoluteness about no more Harry Potter will probably never be broken, even with the epilogue. It can be set in the same world and not have Harry be the central character, and thus, not be a Harry Potter book any longer.