As others have said, the parade won't affect Peter Pan. I think the only attraction that shuts down due to the parade is Storybook Canal Boats (technically, the train also shuts down briefly while the parade is enroute, but the train is not operating at this point). Fireworks, on the other hand, results in the closure of a lot of Fantasyland and all of Toontown. In FL, Mr. Toad, Peter Pan, the Castle Walkthrough, Snow White, Pinnochio, Alice, and Carousel are closed (I'm not sure about Dumbo or the Tea Cups). In my experience, FL tends to re-open somewhere around 15 to 30 minutes after fireworks ends, so if fireworks are at 7:40 pm and the park closes at 8:00 pm, it's unlikely that FL would re-open. If the park stays open until 9:00 pm, then there is a better chance that it'll re-open after the safety checks are completed.