Firstly, I may be late to the following, but in regards to why Fang was made Female, this was a choice made in accordance with Rule 93.
Three Females Rule: There will always be either one or three female characters in the hero's party, no matter how many male characters there are.
And on original topic, I don't like Lightning at all. I would on about why, but it's rather irrelevant.
That said, I like the Idea that we have a female lead who doesn't even so much as have love on the mind.