I have been listening to the song for a while now and the words "sound of guitars" and the "songs" are irritating me still and make it not too easy to accept the last few ideas very easy, although I wrote something different a few hours ago..
What about this: Back to Kitty: She's a writer (a poet?), has published her third novel last year. So maybe it's about being creative and the ability to just let it go, after having created it, giving it (novel, song) away to others now? The first verses could just show how MK admires her for going so deep into imagination and the creative process, and now the novel is ready, she's coming home, back to reality, in a way.
The hardbitten stranger, deaf as a post, could be the critic/reviewer or the public in general. After a long and adventurous creative process, it may be not too easy to let the produced art (novel/song) go - also to expose it to critics. Mark is more experienced in dealing with criticism after all those years. And she has taken the big adventure of writing this or these books, unafraid and so on, and the hardbitten stranger, deaf as a post, he can't know the story, can't feel the pain, stands at the fire, where the poet's dreams roast... Mark would never call himself a poet, so maybe it's about that.
We learned that Let It All Go is about a similar theme, so maybe about an artist that has to learn to be confident in what he does - and Kitty was just my first example. Mark's songs always are generally applicable. Why not thinking of one of his sons, doing his first steps into song writing...
The songs and the laughter at the end could come from him trying to comfort her, trying to console the hurt writer's soul, because of love. The vagabond wind might imply that not only songs and laughter, but also the words of the critics are flying away in the sky and therefore are not important. The music of this song shows that it has a deep warm and loving theme, whatever the explicit lyrics are about.
Phew.
I am sure I will come up with another theory about this tomorrow. This song is very evil in a way. And I wish MK would give a small hint that would help us to understand it. he often did it in the past. For example the mentioning of Sonny Liston made it very easy for me to understand and love Today Is Okay. Patrick O'Brians name helped a lot to understand Haul Away. Why not a single little hint for us?
LE