Haha yeah, I also get fairly easily distracted. In all cases, but especially when Andrew-related things are being discussed.
So, if Alfie's that chill and all, I can imagine they'd get along well enough and be friendly. Besides, while Kieran isn't often stoned, he'd probably smoke up with him once in a while. He'll try anything as long as it's not some crazy-hard drug.
I don't know about Sara and Kieran, if only because I'm not really sure how they'd know each other or anything like that. We could talk about it and see what they'd have in common, something like that.
As for Darcy, I think they'd probably get along, although Kieran would tell her if he thinks her boyfriend's bad is shit (which he would, most likely). I don't know how that would go down with her, haha.