while harry potter and draco malfoy were rational mature beings the females of your story had not so much luck. the most complex character was snape himself who was cunning, intense and intelligent but had the emotional maturity of a 15 year old (and in that way does not divert from jkr's snape).
i liked your ending better than jkr's ending because it avoided potter casting the killing curse despite his "ability to love". - or in other words: your end makes more sense.