I like Peter/Susan to a degree, like, I'm not a huge, huge, huge fan of it but I like it well enough. I get what you're saying about the pairing sort of leaving out Edmund and Lucy, but I feel like I can explain why I still like it and how I feel it doesn't exclude the younger two.

I like Peter/Susan by themselves as a stand alone pairing, but I also like it (squick warning: discussion of polyamorous relationships ahead) sort of layered wih Pevencest in general. Obviously not explicit orgies because I just can't do that, but in the subtextual kind of way, brushing hands and such. To me, Peter/Susan is a part of the more all-encompassing Pevencest relationship, but they also have a bit of a special connection because of them being forbidden from Narnia earlier than their youger siblings.