I like sanguinity's point about the parallels between Keith and Alison, and I like the way you add to them, as well: that's a good point about Ewen's gentleness both with Keith and with Alison. Gentleness in the sense of being a gentleman. : )

Although we do see him spoiling for a fight as well, both in Edinburgh and during the war! But of course that's within a context where it's honourable for him to use force.