Did Snape think Draco was to kill Harry instead of Dumbledore?

[vmonte]

No: HPFGUIDX 140134

Steph wrote,

Has anyone ever wondered if Snape pretended to know about the plan,
but figured that it was Harry who was going to be killed?
Maybe I missed something, but I was under the impression at first
that this had to do with Harry not Dumbledore. And for some reason,
even though I do not want to believe that Snape is really evil, it
appears more likely that Snape would be inclined to help kill Harry
than Dumbledore.

vmonte:
Yes, several people posted this thought already.

http://groups.yahoo.com/group/HPforGrownups/message/133284  

vmonte responds:
So, the idea is that Dumbledore is trying to save Draco's soul and
when he sees Snape he pleads with him via legimens/occlumens
(whichever applies) to strike him down for Draco's sake?

Why not just have Snape grab Draco by the scruff of his collar and
drag his ass into hiding instead. Then get his mother and ship them
off together (who cares what Draco says--I mean your still keeping
him from doing something that is wrong--right? Isn't he going to be
in worse trouble in book 7 when Voldemort finds out that he was
incapable of completing his mission?).

So, instead, Dumbledore says: "I'm dying anyway, the best thing for
you to do would be to kill me Snape---pleeeeease. I realize that I've
not given you the job of DADA because I was afraid that you might go
back to the dark side (and start killing again) but you know what?
Forget what I said. JUST DO IT---PLEEEEASE."

Doesn't it make more sense that Snape was forced to kill Dumbledore
because he made a pact with Narcissa to finish the mission Voldemort
set for Draco if Draco wasn't able to do it. If Snape did not kill
Dumbledore, Snape would die no? Wasn't that the pact? It seems more
in character to me that Snape felt he had to kill Dumbledore because
there was no way he was going to die because of Draco's cowardice. I
mean Snape evens shoves Draco aside as he walks up to kill
Dumbledore. He shows no tender compassion for Draco's struggle.
Snape is not the kind of guy that would die for anyone---JMO.

I'm betting that Snape had no idea what Draco's mission was at first.
And that he just assumed, incorrectly, that Draco was supposed to
kill Harry. I could see Snape willingly go into that kind of pact
with someone. It's not until later that he realizes that Dumbledore
is the target. When he sees that Draco cannot kill, the only thing he
can do is murder Dumbledore, grab Draco, and run the hell out of there
before anyone realizes what he has done.

Vivian