Okay, my analysis, such as it is.
#1 I picked female. I could say I cheated, since I could tell you who wrote it too.
But, if I didn't know I still would have gone with my answer. The trigger for me, if you want to call it that, was the use of the word damsel. Once by the good guy and again by the baddie. I don't think a man writing this would have gone with damsel, and certainly not twice. And definitely not some street punk unless he did because he was sneering at the good guys choice of words. The other was the use of "insanely small penknife." I don't see a man using insanely this way, either another word or none at all in this instance.
#2 I picked male. This "Sweat crept down the side of her face" I think would have been worded differently by a female. Sure, we use the word sweat but in this instance more would have been used to define exactly what she was feeling. And this "She put a look on her face" I feel would have been worded differently by a woman. The use of put a look doesn't ring female writer to me.
#3 I picked female. Okay, guys are, in general, not going to notice that the color of their car compliments what the woman is wearing. He's going to be checking other attributes. That's what I call a guy thing. "a fuss of wind underneath her dishwater-blonde locks" does not read male to me. A fuss of wind isn't what a guy would be thinking. And do most guys even know what dishwater blonde is? "She slowly peeled that neck of hers around" is a bit more descriptive than, I think, a guy would use. She slowly turned might be more like it. "the hem of her dress slide down her velvety legs" was the capper for me. A guy would watch the hem of her dress slide "up" to reveal more and he would use something different than "velvety" to describe what he was seeing. If nothing more, it was this last sentence that decided me.
#4 I picked male. No words or sentences that jumped out at me, but there wasn't any sense of what the day was like or the place either. In the country, I guess, but it could have been the edge of a small town. I had no hint of the ages of the two women or what feelings there are between them. There wasn't a lot of connection between the two.
#5 I picked male. Some mentioned the shoes, but a guy could have done his research, even if to ask a few female friends or relatives. Really, this was a tough one for me and, as I said, it was tricky. I felt it could have been a male or female writer, so it was more a matter of picking one at random.
#6 I picked female. In a way it was a gut feeling. On the other hand, this writing reminds me of a certain author, but I have no idea if she contributed or not. It just "felt" like her to me. If it isn't her, that's still a complement from me.
Other than that, I had nothing jump out at me that this was male or female.
#7 I picked female. No words in particular to draw on. I'm afraid my decision rested on the husband's mention of weight, and the weakness of the wife in being placative. And that sounds weak to me for a basis, but it's all I have for this one.
In conclusion, I don't think these scenes were written in a hurry to try to deceive us in picking the gender of the author. Each one dropped us into a scene to show us a small bit of the story. I felt each one was tightly written and quite good. My analysis is only from my own perspective, right or wrong.
Oh, and I haven't read #8 yet, but I will.