Couple of questions after CoS reread

[dumbledore11214]

No: HPFGUIDX 125437


I have been rereading Cos and had couple of questions. I do not 
remember those being discussed recently, so if someone could refer 
me to the message numbers, I will be very grateful. Tonight 
Yahoomort was just too much to handle.

Remember when Collin is petrified and McGonagall and Dumbledore are 
having the following conversation:

"It means," said Dumbledore, "that the Chamber of Secrets is indeed 
open again."
Madam Pomfrey clapped a hand to her mouth. Professor McGonagall 
stared at Dumbledore.
"But, Albus... surely... who?"
"The question is not who," said Dumbledore, his eyes on colin.
"The question is, how..."
And from what Harry could see of Professor Mcgonagall's shadowy 
face, she didn't understand this any better than he did." - CoS, 
p.181

Now, it is a fact that Dumbledore suspected Tom Riddle back in the 
days, right? Does it mean that he knew for sure that Riddle/Voldie 
is back in Hogwarts? 

If said conclusion is true, does it mean that Harry's struggle in 
CoS was also just a test or at least half-test ( I am of the firm 
opinion that Philosopher stone was a test and the only thing which 
Dumbledore has not anticipated was him leaving school)?

Did Dumbledore know for sure what was going to happen and the only 
thing he did not anticipate was Lucius making Board to suspend him?


Second question. When Hedwig brings Harry a Cristmas gift from 
Dursleys.

"She nibbled his ear in an affectionate sort of way, which was a far 
better present than one that she had brought him, which turned out 
to be from Dursleys. They had sent Harry a toothpick and a note 
telling him to find out whether he'd be able to stay at Hogwarts for 
summer vacation too." - CoS, p.212, paperback.

Let's assume that Dursleys were serious when they wrote a note. We 
all know the drill about Harry's protection, right?  Does it mean 
that Dursleys were not informed about the nature of the protection 
by Dumbledore? That he definitely must spend some time there.
Does it mean that Dumbledore was still keeping secrets at the end of 
OOP and Harry does not necessarily have to return to Dursleys every 
year and can  skip a year or two.

Does it mean  that Dursleys were hoping that protection deal will 
stop when Harry goes to Hogwarts?

What does it mean?


Alla