Nothing wrong with trying to make a wise decision but we need to not let our hearts get hard and not lose our wonder. Try to be optimistic. At the end of the day, you can't know what will happen with a woman. Sure there might be signs that they're a good or bad mate but you can't know for sure. I felt you sounded rather cynical and I don't think that's a good thing. This article on relationship might help you in making good decisions. This is a good video on not losing awe and wonder. It's a bit religious but I think even non-religious people can get something from it.