Few small plot holes I see. The first is his fear about being recognized after his change in appearance, actually I'm surprised he let his 'family' see the new him as that is something that could be reported to Dumbledore and others.
The other is the Croxaeus(sp?) family. How is Harry related to them and how many people know of that relation. Cause he just gave his name for an official report and if the family is as well known and wealthy as you made it out to be then people are bound to notice the new young lord of the family showing up and want to meet him.
On other matters can I hope that the names Fleur and Tonks in the characters list mean that there will be some romance there. Especially Tonks since it is early for her to show up by canon and she is a fov of mine.
Also I suggest sending Sirius a care package of some clothes, a spare wand, wizard tent, and food under preservation charms if he can't just ask him to move to a Potter property for secrecy sake.
More soon please.