LinkLover, I won't say I agree 100% with your stance on love/hate, but you do make an interesting point. It's really all subjective, but there's a fine line between love/hate; however, there's a similar line between love and any other emotion. I think anyone who's experienced it first hand knows that love (or a crush, etcetera) can be a delicate thing, especially starting out. There's a lot of uncertainty and, personally, I need some level of assurance. It's just the way I am.
So there are times when I feel entirely confident about how things are going with someone, and times when my entire perspective is shifted to something else based on something they do. By my very nature I become jealous and insecure, though I do make an honest effort to remain primarily optimistic because that tends to work out for the best in the long run.
Love, I think, isn't really something you can define so easily as a concept. It's an abstraction. It's not so much an emotion as it is a collective of multiple feelings associated with another. You can't pin it down, it can be elusive, and there's no definitive answer to what it is. So you have a point. At the same time, I don't think love and hate are the same concepts. Love can very easily become any number of things.