The 'I love you' thing needs to be taken into context a bit, it's not because it's not said that way in said country that elsewhere it isn't either. I know plenty of women (no men, though, because yeah, women and men are different) who says 'I love you' on a daily basis to each other and the like, they're not in a relationship at all, heck one of my oldest/best friends is a woman who says that to me, and I say that to her, it's purely platonic, we've been through a lot of shit together (and younger we both were wrecks, so a relationship wasn't possible) but there's nothing ambiguous.
DPC comes from Sweden, ok he's doing a game based in USA but he's still from Sweden, I suppose they're just way more open there than say the weirdly 'prudish' country that is USA where swearing is considered 'bad' and 'fuck' is censored. I'm from Canada (Quebec more precisely) and swearing here is just common.
Just examples, cause I don't see Bella and Jill hinting to a lesbian relationship all of a sudden, like someone already mentioned, to me it's purely an older/younger sisters thing.