All I've heard about it is that the answer lies in the power of Love.
Not sure about the film, but certainly wasn't my impression of the book.
Maybe, but from what I understand a lot of the plot revolves around who loves whom, and how love is the be all end end all when it all comes down to it (convincing the Host).
It's been a while since I read it, but I don't remember any sort of dating scenes like that. It's definitely not a romance novel.
The plot for The Host revolves a small group of people resisting the aliens after the fall of Earth. It was about these folks simply trying to survive and not get caught, more of a post apocalyptic vibe.