Were there other motives for placing Harry with the Dursleys?

Question

It is well established that Harry had to live with relatives in order for the blood magic protection his mother placed on him at the time of her death to work. This answer, however, additionally posits that:

we see in Snape's memories in Deathly Hallows that Dumbledore manipulated Harry's childhood to encourage the development of various character traits (such as placing him with the Dursleys in order to humble him) that would help him in what he eventually would have to do.
_{emphasis added}

There is also no doubt that Dumbledore manipulated Harry to a great extent (omissions, half-truths, and outright lies). One could argue that Harry learned humility growing up as a Muggle with the Dursleys, instead of as a celebrity living in a wizarding household. My question though is there any canon evidence that would support the fact that placing Harry with the Dursleys was for any reason other than his protection with other lessons, such as humility, simply added benefits?

Answer 1

Dumbledore outright says that placing him with his Muggle family will help him to learn humility.

‘It’s the best place for him,’ said Dumbledore firmly. ‘His aunt and uncle will be able to explain everything to him when he’s older. I’ve written them a letter.’

‘A letter?’ repeated Professor McGonagall faintly, sitting back down on the wall. ‘Really, Dumbledore, you think you can explain all this in a letter? These people will never understand him! He’ll be famous – a legend – I wouldn’t be surprised if today was known as Harry Potter Day in future – there will be books written about Harry – every child in our world will know his name!’

‘Exactly,’ said Dumbledore, looking very seriously over the top of his half-moon glasses. ‘It would be enough to turn any boy’s head. Famous before he can walk and talk! Famous for something he won’t even remember! Can’t you see how much better off he’ll be, growing up away from all that until he’s ready to take it?’

_{^{Harry Potter and the Philosopher's Stone}}

Dumbledore also seems to be a great believer in the sanctity of the family bond.

‘Yes,’ said Professor McGonagall. ‘And I don’t suppose you’re going to tell me why you’re here, of all places?’

‘I’ve come to bring Harry to his aunt and uncle. They’re the only family he has left now.’

_{^{Harry Potter and the Philosopher's Stone}}

Answer 2

The (real?) reason why Harry is raised by the Dursleys is mentioned in DH:

(Snape) “I have spied for you and lied for you, put myself in mortal danger for you. Everything was supposed to be to keep Lily Potter’s son safe. Now you tell me you have been raising him like a pig for slaughter —”

“But this is touching, Severus,” said Dumbledore seriously. (DH)

Note that Dumbledore doesn't deny Snape's observation, Dumbledore wanted Harry to be raised like a pig for slaughter. The Dursley's abuse is instrumental to this: They make him have no sense of self worth, believe that everything bad that happens is his fault and responsibility. As a result of his upbringing, he has no problems walking to his death, it seems natural to him.

This is not about keeping Harry humble, it is psychical abuse.

Dumbledore says that Harry has to die because of his scar. Would Dumbledore want to remove Harry's scar? No.

(Dumbledore) “Even if I could, I wouldn’t. Scars can come in handy.”

Note that Dumbledore knew how Harry's time with the Dursleys would be, even before he placed him there:

“You had suffered. I knew you would when I left you on your aunt and uncle’s doorstep. I knew I was condemning you to ten dark and diffi­cult years.” (OotP)

But he also had Harry's misery confirmed by Mrs. Figg:

“Dumbledore’s orders. I was to keep an eye on you but not say any­thing, you were too young. I’m sorry I gave you such a miserable time, but the Dursleys would never have let you come if they’d thought you enjoyed it.” (OotP)

So Mrs. Figg and by extension Dumbledore were aware that the Dursleys were not indifferent towards Harry, they actively wanted Harry to be miserable.

It would have been easy for Dumbledore to make sure Harry is treated decently, but he didn't want that. Notice how just the address on the letter leads to Harry having his own room:

“Vernon,” Aunt Petunia was saying in a quivering voice, “look at the address — how could they possibly know where he sleeps? You don’t think they’re watching the house?”

...

“Er — yes, Harry — about this cupboard. Your aunt and I have been thinking … you’re really getting a bit big for it … we think it might be nice if you moved into Dudley’s second bed­room.” (PS)

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On the other hand, we don't know what kind of protection Harry may or may not have from living with the Dursleys. He is obviously not protected against the Dursleys. But he is also not protected against the Dementors in OotP. Maybe Harry is protected while inside the house, but he doesn't spend his whole time inside.