Rumors that Harry was a Dark Wizard

[Kristen]

No: HPFGUIDX 134494

I have questions about the rumors that Harry was a Dark wizard.  I 
don't recall seeing much discussion of this yet (but I haven't been 
able to keep up with posts and the search function isn't working 
well, so bear with me).

In HBP Chapter 2, "Spinner's End," Snape tells Bellatrix and Narcissa 
that "when Potter first arrived at Hogwarts there were still many 
stories circulating about him, rumors that he himself was a great 
Dark Wizard, which was how he had survived the Dark Lord's attack.  
Indeed, many of the Dark Lord's followers thought Potter might be a 
standard around which we could rally once more."

To me, this assertion about the Death Eaters' beliefs was a 
surprise.  I went back through the books thinking of evidence that 
might back this statement.  I'm guessing that Snape isn't simply 
making this up to throw off the two sisters, because his reference to 
the belief of "many of the Dark Lord's followers" would be fairly 
easy for Bellatrix to verify.

Is this the reason for Snape's questioning of Harry at the first 
Potions class (SS ch 8)?  (Powdered root of asphodel to infusion of 
wormwood, where to find a bezoar, monkshood/wolfsbane.)  Is he trying 
to suss out Harry's familiarity with the Dark Arts?  (The HPB, of 
course, adds additional signficance to the bezoar.)  

I can't seem to find  evidence of any other professors testing Harry 
in this way . . . but what about Ollivander's ambiguous "great 
things" statement (SS ch 5)?

Draco is reasonably friendly to Harry in Madam Malkin's, before he 
knows who Harry is(SS ch 5), but after a brief attempt to suck up 
with the "wrong sort" statement in the train, he quickly takes 
offense and lobs the "go the same way as your parents" comment(SS ch 
6).  If the Malfoys suspected Harry could be the next Voldemort, it 
seems like Draco would have been more persistent in trying to 
establish good relations.