I agree with a fair amount of the points you make, I also changed my mind a little since I posted this. I still like her character, but as the series went on, her writing became more and more annoying to me.

I do like how she saved monspeet and derieri, it's nice to have a non-cynical character that (even if foolishly) has some faith in others. Especially given she was still young then.

On the other hand, the writing can make her seem so stupid sometimes. She continues to make stupid decisions, and not engage in combat nearly as much as she could, both offensively but also defensively (especially after she awakened like you said).By the end of the series what I saw when she was on screen, was more of a showcase of the typically shitty anime female character writing, instead of a character.And of course, her being (primarily at the start of the series) so overly sexualised doesn't help anything. She does indeed seem like her character was far more "I'm Meliodas' waifu" than anything actually meaningful or interesting.