What about Dumbledores Death?

We know that JK has said that Dumbledore is definately dead, but think of it objectively; if you were about to release the last book in a major series and one of the biggest pieces of news was being ruined by a theory, would you let the theory pass or absolutely deny it outright? I think that she maybe said that so that when people read book 7 they get a big suprise.
I concocted a lot of this theory with my english teacher and a few mates, during an extremely tedious lesson.
When Dumbledore says 'Severus, please' we think he was trying to tell Snape that Harry was still there. As Snape didn't speak the word sof the curse, he just delivered it, it may not have been the killing curse. After theses events it would have been so much easier for Snape to spy on Voldemort without any suspicion, whatsoever. In turn this would mean that Dumbledore was in hiding and with Voldemort thinking that Dumbledore is dead, he would have happily gone about his business killing - at this point Dumbledore will have the element of suprise and I think therefore be able to assist Harry on his quest to kill Voldemort.