I cant' possibly see how Snape would be related to Harry... I think that one is just too far fetched and improbable... *hrmm, please dont' take me totally disagreeing with your theory personally jodelientje...
*
But, I do think that Snape might ahve been in love with Lily... and I like your first point azn. I did think that point 4 was probable too, but then reaslied this... I seem to recall DD sayinghtat Snape was spy for while, and killing James and Lily was the last thing he planned to do... so wouldnt' that kinds put Snape changing sides and being a spy before Voldie decided to off James and Lily???
*have I gone off topic again???
*