Yes, Draco does! Still, he and Pansy are not crazy or anything, just spoiled brats. Really, it's called character development, but she chose not to do that.
Your dad is right. Also, many deaths in DH can easily be explained away, too. Which is just about every fic 've written since that book came out.
YES to Luna/Harry having a connection! Ginny (and to a lesser extent, Hermione) smack of Mary Sue, as does the most obvious one, Fleur. Never mind that she called Angelina Fred's ex...one Yule Ball date, where he ignored her to chase after Ludo Bagman with George, does NOT an ex make! I think she should have spent more time exploring those details, but that is just me. (Even if I don't ship Ange with either twin, she's too bossy for Fred, and with George? Just doesn't click for me.)
I think so too, but in most RPGs still, it's all about canon (unless it's the dead coming back to life). It's frustrating! I found a game where every character who died in DH was revived...EXCEPT for Fred! I was NOT happy at all to see that. People can bring back Tonks, Remus, Sirius, Severus...why not Fred? It's not right.