I liked lots of stuff in this chapter: First Harry's apparition lesson and how he got excited when he got his owls and apparated all over the place while doing cartwheels. That was cool. I liked how he went to 12 Grimwald place and snuck up on his friends who were planning to sneak out and see him. You know, I bet that Petunia is a witch in canon. JKR said that she wasn't a Squib but that there was more to her that meets the eye. If she was taking Harry in because she was being blackmailed and agreed only if Dudley never was contacted by the magical world.. interesting things and theories can come out of that.

I like the relationship Harry is having with Remus. I wonder if Remus is going to die soon... hmmm, that would almost be cruel to Harry but I don't think that we writers are known for being nice anyway. XD I like your writing when Snape came in, nice tension and really interesting tense feelings strung through them. Overall, I feel that you could improve the writing, but that will probbaly something that you'll be able to see over time yourself.