Why would Snape want the DADA position? (Was: It's over, Snape is evil)

[ceridwennight]

No: HPFGUIDX 137822

Ceridwen:
I'm not sure if this is post number three for me, or number four.  If 
it's four, I apologize and promise to bang my head repeatedly against 
the kitchen wall.

justcarol wrote:
> Then, after changing sides and spying for Dumbledore "at great 
> personal risk," he applied again, having been sent by Voldemort as 
> a spy but having revealed his true loyalties to Dumbledore and was 
> given the position of Potions master....

Ceridwen: I'm snipping down to an idea, but it's so hard, the post 
was very good!

justcarol:
> After Voldemort's fall, Snape reapplied for the DADA position
> repeatedly, yet he could not have failed to see that the jinx (or
> curse) on the position was no mere rumor among the students.
*(snip)*
> Maybe repeatedly applying for it was part of his cover as that was 
> the position he had originally been sent by Voldemort to apply for, 
> but surely he didn't really want it?
*(snip)* 
> Carol, noting that the villain of the book is Voldemort, not Snape,
> and all the characters, including Dumbledore and Snape, are caught 
> in Voldemort's web


Ceridwen:
Duly noting that the characters are caught in Voldemort's web, which 
is indicative of the point.

If Voldemort placed a curse on the DADA position, why would he send 
his own man in there to take it?  Unless the curse (or hex) can only 
be broken by one of his loyal followers applying for and receiving 
the position?  I'm not counting Fake!Moody here, since Crouch jr. 
didn't apply for the position and win it himself.

If there wasn't something significant about the rotating DADA spot, 
then why make it such a noticeable thing in the books?  One reason 
might be for comic relief as an aside to showing how desperate 
Voldemort is to get inside the castle.

Could be.  But I don't think so.  When 'his man' has the post, he 
doesn't use that plant, but another one, a student he might hope will 
die, to affect the DEs' entry.  Has Snape gotten the item LV wants to 
use as a horcrux?  Because Voldemort *apparently* didn't come in with 
his people to get it and use it himself.  What's the big deal about 
getting his own man in there?  What's the point?

Sorry for getting so wound up.  What I want to ask is twofold, it 
seems:  First, can the curse/hex on the DADA position only be broken 
by the outright hiring of Voldemort's man?  (If so, then the curse is 
not yet broken, maybe that tells LV more than anything else could 
have?) and second, Why did Voldemort want one of his people in that 
position?  Just to tweak Dumbledore?  To lead likely candidates for 
the Dark Mark into the fold while giving false info to students who 
might fight back?  To get the last horcrux item for LV's collection?

Ceridwen, who hasn't thought it out well enough to type it yet, but 
hoping someone'll understand.