Your writing is good, but i'd like you to write not only about peripheral characters but also how their behaviour affects central canon characters, so far you've written just 2-3 chapters out of 50. Also in peripheral characters you should devote some time to develope villains too, coz hero is no hero untill villain is worth something. The way you're writing it's good to read of course, but in terms of overall story, the plot doesn't progress without protagonist & antagonist.
Author's response
Thank you!
I am keenly aware of the lack of obvious, active antagonists and am unhappy about it. Their absence so far is a planning error -- I kind of backed myself into a position where I couldn't just toss them in as quickly and easily as I had assumed I could, largely because I _utterly_ misjudged how many words it would take for me to get to various points in the story. At the outset I would have thought that, by 200k words, I would have gotten all four time-travelers in and gotten through the end of the 91-92 school year, at a minimum. That totally didn't go as planned. :P So the short response is "argh! I know, I know!" At this rate you will all identify the first real villain at the 400k word mark (well, hopefully not).
That said, just because readers _like_ a character doesn't mean _I_ think they're a protagonist, or on the side of Good and Light or whatever, or that I think their actions successfully help the side of Good and Light or whatever.
As to the central/peripheral thing, that might be a fundamental property of the story, depending on what you meant. For me, "central canon characters" means (so far) Tonks, Dumbledore, and _for this year only_, Charlie. The sidelining of main characters from the books is one of the primary conceits of the story I'm trying to write -- I am deliberately _resisting_ the temptation to check in more often with Harry, Hermione, Ron, and so on, because this is _not_ their story. Some reviewer said something to the effect of that making it less like fanfiction and more like a borrowed universe, which is accurate and fair, but also something I'm doing on purpose. You are totally allowed to not enjoy that!
Of course, I have full confidence that, since Harry and his friends are used to getting the important roles, they will eventually grow pushy enough to force me to pay more attention to them. Heck, I never intended to spend so much time on Dumbledore -- he's a good example of a "pushy" character. :P
Again, thank you -- I appreciate reviews, even ones reminding me of things I already feel guilty about!