For ease and to save from walls of text, you can see my character intros here.
Important people for Neville: Ginny is definitely his friend. Would he have still asked her to the Yule Ball? Seamus is also his friend. He unabashedly and unashamedly flirts with Neville.
The others will be friendly.
Important people for Remus: Primrose is most important. She calls him Uncle Remus and loves him dearly. She's just about 23 weeks pregnant (it was an oops).
Everyone but Joe had Remus as a professor at Hogwarts, so they'll be good to him. Joe will be a bud.