Well, I don't think that I have reviewed your story yet but I will give it a crack. First, it isn't yours quite yet, but I'm sure that you will do fine. You will want to go back and remove your note chapter about the author's death, which I agree is quite tragic and you should provide a dedication note in your chapters in regards to your friend. Second. I would suggest that you map your book. If you don't know what that means, I will explain.
Prior to writing any chapter you need a map, and that will get you from the beginning to the end of the chapter. I would also suggest that you do it overall for the book. If you had any conversations with the original author, in regards to the wishes for the story or how it should go, keep that it mind and talk to Taylor's sister, if anything that was mentioned about this story, take it to heart for keeping it in.
When you map, you're really doing bullet points that you want to hit. I would suggest doing a map for the whole story overall and then take a look at the map once you're done. Once you're done, break it down into chapters. No more than four bullets should be for a chapter. You want to make sure that you hit them, but once you do. Map the chapter. Again, looking at what you want to hit bullet it out to your hearts content.
Once that is done, start writing it out. I hope that is helpful when writing. With what you're doing now, betaing an existing chapter, you will find it's quite a bit different once you're putting your own work into it. It's really fulfilling once you've received your first review, but it can also be fulfilling to get your first flame as well, so keep that in mind.
Suggestions. Well, I'm curious first as to how far you're planning to have this Ron and Draco duality. It's basically the same character just different houses. There needs to be another confrontation with Ronald coming up as well as Draco. You may want to look at pairing them up for the GREATER bad.
Second, this is third year. You need to have Harry learn the Patronus charm as well as having more interaction with Sirius. There has to be a confrontation or explanation happen between Harry and Remus in regards to Sirius. Also, where is Ron's rat in all this? This is crucial. Next, since you've formed a bit of an alliance with Harry and the twins, there is one thing that has not been address so far in this story and that is the previous year. Did Lucius Malfoy give Ginny Weasley the diary in your AU? If so, why isn't she been a part of this story so far? Did Tom get resurrected last year and it hasn't been addressed? If not, where does Ginny stand in this story. True to form of canon, so far, she is a non-character.
Next, I would like to inquire as to whether Harry will be going to Hogsmeade on the first weekend. It has to be considered and whether or not it will be a focal point as it was in PoA. This is where he learned that Sirius was his godfather. This is also where Harry learns about the Marauder's Map. Will he get possession of the map or not. If he does will he mention it to Remus? Will Remus explain who the Marauders were? Will Harry find Peter on the map? Will he share it with Sirius or Remus? There has to be clear lines drawn and when that happens you have to decide which way you want to go. If you alter the canon, which has already been done, well, you have to decide what will be the outcome. You also have to decide whether or not Peter will be captured this go round and if so, who will step up to the plate to do the resurrection attempt.
Next, covering First and second year. You mentioned the troll incident, but what of Quirrell? Was he there, if so, did he get the stone or was the stone ever a point, if so what happened in this regard. When starting a story at the point in time that you did, you have to make sure to cover all the bases. This can be easily done with a conversation with Hermione or Ron or even Neville. Are you going to keep Neville one of Ron's lackeys? He doesn't really seem the lackey type.
Last, third year is an important part of life. They're 13 and hormones are running wild and it will be time to consider dating VERY soon. I hope that you have that covered.
WELL! This has turned out to be the review from HELL. I like the story so far. I do hope that there will be a resolution for Harry's hearing and something comes of that but that is just a hope. I take it from that twist in the story that the original author knew someone who was hearing impaired. I wish you luck in taking this story on and hope that you do it justice. I do hope that this review was somewhat helpful as that was it's intent.
Sincerely,
Geovanni Luciano