I like that it's consistent with Lee's characterization, I just don't think it's a big deal for that reason. Standing up to Norman Osborne and telling him to leave her children alone isn't that much different from standing up to Spider-Man and telling him to leave Peter alone, especially since she probably thought she had more reason to be afraid of Spider-Man than of Osborne.(As for Conway's characterization, he pretty much trashed the character in the little that he used her before he killed her off. Writing female characters is not one of his strengths.) I think we're coming at this from different perspectives. My image of Gwen is as she was originally written, yours is 30 years of perfect dead girlfriend stories. In that context, I don't disagree that this kind of story could be an improvement. Peter SHOULD romanticize her in his memory, but that the way memory work, not objective truth.
You have a point about "Norman, business tycoon and supervillain, being threatened enough by a teenage girl that he felt he had to kill her" being a better story than "superhero's girlfriend gets dumped off a bridge," but this isn't just a story about a supervillain and a teenage girl," this is a story about Norman Osborne and Gwen Stacy, so it has to fit in that context (And like I said last time we went over this, you've made it sort of fit, but it still requires a lot of work that they should be doing, not you.), and it's a story in a comic about Spider-Man. If he killed Gwen because he felt threatened by her, you've made Spider-Man irrelevant in one of his strongest stories. Plus, it doesn't quite fit with the actual story, where he wasn't looking for Gwen, he was looking for Peter and found Gwen.
I don't know if it's a good idea to bring theories about creators' wish-fulfillment into this discussion. It might be a bad protrayal of Gwen Stacy, but it fits in with the theme of Marvels where Phil Sheldon becomes bitter and cynical, and there's the possibility that he's romanticizing HIS memories of Gwen to fit in with that. Which is a problem when those memories are presented as what actually happened.
But if we're doing that, we can also look at Sins Past as an aging fanboy's fantasy about defiling the 19/20 year old virgin and suffering no consequences. That was my problem with a lot of defenses of Sins Past, both official and not. They came across as an extreme version of a Madonna/whore complex, where all women are really whores deep down, and giving one sexual sins to atone for makes her more realistic. Using "there are some women who do that" as a defense without showing why it applies to this specific woman is essentially saying "there are no women who wouldn't do that."
That said, I have no sympathy for the "they made Gwen a slut" line of criticism, either.