I think, for me, a bigger time jump would be needed to make this work given all Ren did to her in TFA. Although, given my general loathing for Kylo… Nah.
No, there isn’t. If they actually had a plan and knew where they were going, it’d be easier to weave in side stories and this and that. There’s a great little YA book, Before the Awakening, by Rucka, that spins a story for Finn, Poe and Rey just before the film and is well worth a look, but that’s about it.
Instead they’ve focused on addressing other aspects and eras via new characters, which is what the Aftermath trilogy was. Given all Ep 9 has to do, certain aspects of TLJ need supporting so that’s where I expect the books to be going for the next two years.