OOC
There are some theories that my friends and I have:
-Dumbledore's Death
We don't think that Dumbledore really died.
We believe that when Hagrid heard Dumbledore and Snape arguing, they were arguing about whether Snape would kill Dumbledore. We think that Dumbledore was telling him to do it if he must, but Snape didn't want to.
When Snape showed up with the Death Eaters, Dumbledore was pleading with Snape, but we believe he was begging him to perform Avada Kedavra, not for him to save his life. We know that, in order for Avada Kedavra to work, the person performing the spell must really hate the person that he/she is performing it on. And even though the book said that Harry could see the hatred on Snape's face, we believe that he was hating the fact that he had to kill Dumbledore, not Dumbledore himself.
So why did Dumbledore appear to die? Well, we believe that The potion that Dumbledore drank to get the horcrux was Draught of Living Death. This potion puts it's drinker into a death-like sleep.
-Who's R.A.B.??
Well, we believe that R.A.B. is Regulus Black. He was a Death Eater (R.A.B. referred to Voldemort as the Dark Lord), and when cleaning the Black Manor in OotP, the group found a locket.
-Horcruxes
Well, this isn't really a theory, it's just kind of an idea that most likely is not true.
We were wondering if PEOPLE can be horcruxes. And if so, wouldn't it be extremly f*cked up if HARRY was a horcrux??? Like, if his scar somehow signified that, and that's why Voldemort can't kill him? Voldemort may have planned to make a horcrux out of the Potters' deaths, and because Lily died FOR Harry, he became the horcrux. I mean, Dumbledore said at the end of his lessons, Harry would know why Lily dieing for him was so important. What if Dumbledore knows (knew) that Harry is a horcrux, and when he destroyed the other horcruxes, Harry and Voldemort would finally be able to kill eachother (which ever happens first).
Anyway, those are just some ideas. Let me know what you think!