You are the man!
I might coyly suggest a means of measuring Love and Hate. How much of your time and energy you expend on obtaining/avoiding something might well indictate the level of Love/Hate. After all, there are exchanges which take place. Going out on a date or getting married and having children are ultimate by-products of that Love. How much revenge you exact and how long you have to spend in prison might be a good indicator of how much you Hate.
Interesting possibilities, but each are falsifiable. You could spend a lot of time and money on an object of your attention, which could be regarded as love (example: (Time+Money)Object = Love). But someone could spend a lot of time and money on a project (like Boston's Big Dig) and grow to loathe what they are doing because it's not making them happy (which runs you right smack into another abstract concept!).
Children could be a good example of love, but the probability of pregnancy does not factor in love between the partners, only the viability of the sperm and egg. If love were factored in, then rape would never produce children (and arguably, a lot fewer kids would be born).
Consciously Inflicting violence upon another person--outside the bonds of parent-child and dominatrix-slave--affords little opportunity of becoming falsifiable. But again, how would you measure it? The only way you could get close would be to use money as a measurement, and even then, it must be how much the victim had to pay to fix how much he was hurt. Using money to measure hate is still falsifiable, because the person could fix themselves for free (given the right connections, of course).