The only way I can make sense of it all is that Snape wishes the two sides would stop fighting with each other and is torn appart to see his friends from the two sides fight.

Did Snape hate Voldemort and want him out of the way as it seems toward the end or was his true alliance with Voldemort revealed through Dumbledore's death?
Did Dumbledore orchestrate his own death or was this Snape's doing?
Why didn't Snape do it sooner, did he need a witness to gain credibility and thus was good or was this credibility merely to re-prove to Voldemort his true alliance?

It goes back and forth so many times... how the heck can you make sense of any of it? Didn't Jo say his true alliance is revealed in the final book, does this mean he is good?

I think Snape was influenced by the love he felt for Lily. He felt this need to help Harry and Dumbledore, however Voldemort enabled him to get the revenge he desired. It's all very complicated. Snape trialed both sides of the arguement, but i think in the end he felt no place in either. Yes, Voldemort seemed to by the most probable alliance need the end of the book, however didn't Dumbledore plan his own death and Snape was forfilling his desire. I have no idea why this character is so hard to read.

true he was driven by love, but he did not feel the need to help harry and Dumbledore his hand was more forced by the fact that his love was to be killed by Voldemort and the only possible way he could think of helping her was to go to Dumbledore.