Augh, this captures them so well. Misa being upbeat and doing everything to earn Light's love, Rem being helpless in the face of it but quietly honouring Misa's wishes. It unearths the heartache I used to have for this hopeless pairing.

But sometimes Misa says something very unlike herself – a few words, a fragment of insight – and then Rem thinks that maybe the girl is totally aware of the fact that Light is just using her for his own schemes … and that she simply doesn’t mind.
This paragraph is just... yes, all of this. I loved that Misa wasn't as stupid as she acted.

And I think the quote you incorporated into the fic is so fitting for Misa. Well chosen!