Impressive reasoning. I read the link, which makes a lot of sense. I can see how Dumbledore, knowing he will die anyway, is pleading not for his salvation but for death. I even mentioned a few posts ago that it wasn't like him to plead. But he's pleading not on his own behalf. As two accomplished wizards, it would be easy for Dumbledore to communicate silently in Snape's mind. Snape doesn't want to do it, but knows he must, hence his expression of loathing. He's hating himself, not Dumbledore, for what he must do.
If this is indeed true, then Dumbledore is in all likelihood dead for good. And Snape is likely still on the side of good. What could put in him better with the Dark Lord than to destroy the only wizard that Voldemort fears?
It also explains why he froze Harry, rather than Draco. He's dying anyway, so escape wouldn't matter to him.
