One thing I think is important to note is that it's hard in any story to represent equality in every direction equally. By that I mean, I think Joss deserves a lot of credit for his portrayal of LGBT characters throughout his many tv shows and comics. Now could you say "Joss sucks because there are few asian roles in anything he has ever done." I suppose you could. But the net result is, Buffy was one of two lead female action stars on TV in it's hey day (Jennifer Garner on Alias being the other one of note, and Buffy predated her). In terms of Joss's female characters only benefitting from a relationship with a male, I would argue Willow and Tara is a relationship between two women where both women come into their own as a benefit of a healthy relationship. It certainly doesn't END well, but what relationship in the Whedonverse does.
Yes, Joss's portrayal of women may be flawed. But I'll put it to you, maybe it's us, as straight men, whose UNDERSTANDING of women is flawed, and constantly evolving. I was raised in a loving home with a strong woman as the matriarch of the house, who was the breadwinner over my father, and who was a professional in the aerospace industry during the 80's. She was very much of, and yet ahead of, her time. To say that I had a more evolved view of women than my peers is an understatement. I was routinely called a fag because I dare look at women as equals. Even now when I say to certain men that women are largely tougher than men, they look at me like I suddenly started vomiting. I also, however, was raised by grandparents from the deep south, and all sorts of colloquialisms and habits found their way into my DNA as well. Growing up it was considered polite for a man to not only hold the door and pull out the chair for a lady (which, I find most women appreciate) but also to use terms of endearment like "sugar," "m'dear," "honey," and "doll," in a casual setting even with women that I wasn't as familiar with. As I grew up I came to understand WHY a woman would possibly be offended by that. I have largely curbed those habits, but they do come out periodically. I'm trying. I'm not perfect and I suspect Joss isn't either, and as a result, neither is his art. I mention all this to frame the argument as such: Joss is one of those hetero white men who is first through the wall in terms of making strong women the focal point of his stories. You are self admittedly admittedly a teenage girl, so you don't remember how "strong women" were portrayed just 10 years prior to Buffy. One character I remember strongly who was deemed a strong women by tv media was DeeDee McCall from a cop procedural in the 1980's called "Hunter." DeeDee was the tough talking sidekick to the titular male character and she was routinely part of the action. But when writers ran out of stories for her and they needed an arc for sweeps, they did what any forward thinking writer would. They raped her. It was a three week arc that was advertised as "very special" episodes, as 80's tv was wont to do. After the three week arc ended...no mention of it at all. No recovery process, no realistic potrayal of trauma, nothing.
Until 2 years later when THEY RAPED HER AGAIN. For sweeps. Both times, they made sure to dress her in long sleeves and pants so as not to insinuate that her wardrobe sent mixed messages that she was asking for it. Take a bow, 1980's.
Joss was a writer during this time too, and the nucleus of the idea for Buffy was born as a reaction to the tropes that were then considered progressive, and now appropriately considered sexist. The teenage girl being followed down a lonely street by strange men, who ultimately corner her....until she kills them all. It's not radical now, but it certainly was at the time, and you can't diminish that. So yes, Joss isn't exactly the tip of the spear in 2012 for the modern woman, nor should he be. Equality is a relay race, not a sprint, and Joss moved that baton farther than most of his contemporaries. Now it's time for someone else.