FicWad

Here the actual spell used on Harry,

The bond of blood is an extremely powerful ancient magic which is formed when a person sacrifices himself or herself for a family member, out of love. The sacrifice creates a lingering protection in the blood of the person who was saved. It is not activated, however, until the charm is actually cast, and it is not sealed and functioning until another member of the family accepts the saved person as his or her own.

Through research and reading the books, from what I can tell, you are correct the protection only works against Voldemort. And only inside the house. Beyond that, Harry would be a sitting duck even on the lawn of Privit drive. He might be protected from death eaters due to the dark mark, but beyond that he really wasn't that protected.

As for why Harry was not protected from Voldeis soul piece is because the Horcrux spell was not cast. Thus the soul piece was not becoming part of a evil object. Harry was a Horcrux in fact, rather than one in practice.

I do agree Dumbledore was evil in many ways, but many heroes often can be fairy evil at times. I digress though, evil is still evil. Though in the draconian society he lived in his actions would have been considered acceptable to some. Even to someone who had only lived in it 7 years.

I did like the story, it brought up very important points. Perhaps in her encyclopedia, when it comes out, might address them.