I liked Arya's plot in theory but I'll have to see how the show executed it...at least in ours Ned and Syrio are alive and well. And Joffrey becomes a human being with needs that aren't just mutilating people. >__> At least people he loves.
As annoying as Yusuke is, she does care for him. She loves her job. But having gotten close to the gang and still having to do her job, she does become isolated. Yusuke almost died again, Genkai came back from the dead, it's a lot for anyone to bear. But with Kurama and Shiori, she has a family, something she hadn't missed in a long time but having them around, reminds her how alone she really is and makes her question how long she can keep doing her job. Koenma relies on her more than anyone else in her field, she's given a lot of burdens to carry. And you know she'd never want to say 'no' to anyone.
And the smut scene, at least their first, I think would be cute and sweet and a little funny/clumsy because they're finally crossing a line. But I think it'll just make everything better and let them show each other how much they mean to one another. <333 And argh, I need to re-write my Shiori part, it's not motherly enough. >___>