I thought it was also influenced by 'Revelation Space' by Alistair Reynolds, in particular the sections set on the ship Nostalgia for Infinity, which in turn I thought was influenced by Dark Star by John Carpenter. This is not an allusion which most viewers would be expected to get, so it's not part of the weighting, I just think Moffat liked that imagery (and I did too - the darkening forest on the space ship is my favourite bit of Revelation Space and I often think of it).
I was watching the episode with my daughter and at the end we were both shouting at the telly 'Oh no you didn't!', not another bloody companion with a crush on The Doctor! However, in retrospect the scene redeems itself for me, in that it's nice to see a girl allowed to be sexually assertive and careless without being punished for it. It reminds me of that old Joe Jackson song 'No, not love she said; don't you know that it's different for girls'.