Oh god. I'm going to regret getting into this thread. I just know it.
I think this thread digressed into one real point of contention. What masculinity is and what femininity is (and whether Shepard is either). The ideas of masculinity and femininity are almost entirely social constructions. Some things can be attributed to males moreso than females (certain spatial task performances) and something moreso to females than males (certain language task performances). And even in the scientific literature they are STILL arguing over whether this is significantly different between genders. But personality traits, styles of dress, etc. are not -- they are social constructions, perpetuated by the society which the person has been shaped by. It's really hard to sort out what is caused by biology and what is caused by environment when they both affect and are effected by each other. And this is something that is not going to be changed except by passing time and relinquishing of old stereotypes. In order to properly classify it, in my opinion, you would need to try and find separations in which there are significant differences between groups that are larger than the usual differences between individuals. We can't find this with masculinity and femininity (why is that word so hard to type--!).
In other words we cannot accurately 'generalize' (what an oxymoron, I don't know how else to phrase it) unless the differences between groups are more significant than the differences between individuals.
So the statement 'Shepard is masculine' is both correct and incorrect. By the current values held by western society, yes. She is masculine. But masculinity is a completely arbitrary title/designation. So the argument to this is that, no-- she's not masculine she is simply a women who carries traits which are, incorrectly, dubbed masculine by current societal values when they should simply be described as 'virtuous' or 'soldier-like' (however you want to call her).
As for the armor issue. I wondered about the breast-plates myself. But since I kept the main body of my armor dark black, I didn't even notice there was a seam in-between the plates. In which case I think that would be a structural weakness since a seam would be waaaay easier to penetrate than a solid plate. The DA:O armor had the right idea, in that case, but damn that helmet!! I wore it to freedom's progress when Tali first recognized me and I was really confused when she somehow recognized it was me in that psychedelic armor (which made me worry it said a lot about my choices/outfitting in the last game haha)