I really like your story so far.
The conversation between Harry and Quirrelmort is amongst the best I've ever read.
Just an idea, you've likely tought of it on your own:
If Harry EVER develops enough interest to build a society (maybe an academic exercise?) they could agree that Voldemort can get all the purebloods, while Harry takes all the muggleborn and squibs. They mutually hide the agreement and other society from their people respectively. (Maybe a nice showdown, killing Dumbles stunning everyone and memory charming everyone to think their side won and noone from the other side survived?)
Looking forward to more goodiness.
sropike