>>4100219A replay is a great idea, since we're probably at least a year out from chapters 3 + 4 releasing. I've been meaning to do one too.
Some missable Noelle/Susie moments for anyone doing a playthrough:
- Talk to Noelle about Susie at the end of chapter 1 and use that save to continue to chapter 2
to get a cute cutscene where Noelle gives Susie a box of chalk- Try to equip Susie's Mane Ax on Noelle
and she'll comment that it smells nice. The item description of the Mane Ax is "forged from the mane of a dragon whelp", which implies that it's Susie's hair- Try to equip Noelle's default ring on Susie
and she'll comment "Smells like Noelle." Not a good idea to do this one though, since to get Noelle to unequip her default ring you have to start the Snowgrave route.- At the end of chapter 2, examine the Ralsei Dummy in Castletown
and Susie will imagine Noelle dressing it up like a Christmas tree, and then wonder why she was thinking that- At the end of chapter 2, examine the cupboard in the kitchen next to Toriel and Susie
and Susie will say that gingerbread sounds like something Noelle would like, and becomes flustered when Toriel remarks on her saying Noelle's name 
