Question: Who is Scarlett? She appears to live with Charles, but not share a bed with him; IMDb refers to her as Charles' sister, but her, er, style of talking is so out of kilter with Charles and indeed all the others that it seems unlikely that she's related.
Question: Why wouldn't Charles' brother be his best man? Or is that not traditional in England the way it is in America? It's not mandatory but is certainly expected, unless the brothers are not close (which Charles and his brother are) or the groom's father serves as best man.