Well, I like your descriptions of upstate New York so far, and they way you balance the descriptions such that you don't describe every leaf on every tree, but do give enough detail that we can mentally see it.
Since Parker seems to like younger boys, maybe she and David might have a few harmless flirtations?
And as far as Charmed and the Door series goes, I wasn't suggesting that Jesse and Marty end up on the Door world, but that perhaps they ride the same bus or something, with Derry and Cally as the last stop on the bus route, perhaps. But if they are never mentioned, not a big deal at all.
Hoping another Door adventure is coming soon!