[quote=elmoro;39405]..but were explained in the books.

1. how did snape/dumbledores portret knew when harry was moved from privet drive? why thought voldemort snape well informed?? he wasnt in the order anymore.
quote]

all the school Headmasters lived in those portraits and could act and think for themselves. Dumbledore would have made plans known to the Order himself earlier I imagine.
Snape as Headmaster in Book7 would have been able to talk to Dumbledore any time he was in the Headmaster's office.

Voldemort would have thought Snape well informed I guess because Snape was brilliant at Occlumency. and also, because Snape did 'kill' Dumbledore. That would have given Snape more leverage than any other Death eater.

so, a bit of trickery (the mind control) and doing the unthinkable (getting rid of Dumbledore).