I'm not sure if I like the idea of Vickers being an android.

I quite like the idea of her acting like one because that's what her father responds better to (a human making herself in the image of an android made in the image of humanity).

It might be fun to reveal that there is more than one David on board by compositing footage from one scene into another.

That way we could have a 'nicer David' who is interested in humanity and a more literally obedient slave who spikes Holloway's drink etc.

There could be a bit of ambiguity at the end regarding which one Shaw has left with.