I was specifically told when I was on course that those were two things that were definitely not allowed -- the tucked french braid and the braid wound into a bun. We were shown pictures right out of the regs, and told, "These are your options. That's it."
Yes, I've seen women doing the other things too, but perhaps it's only because no one has jacked them up for it? I know as a Jr NCM, there's no way I'd tell a female MWO, "Ma'am, your hair is out of regs," unless I wanted a world of hurt. I get jacked up for my double braids all the time, so I started carrying around a print-out of the pictures from the dress regs. I find that most times, it's only because it's not super commonly seen, and males aren't always sure about the female hair regs, so I have no problem sharing them.
A parting of the hair is not the same as a picture of a bun. I don't think it sounds silly at all. I don't see anything wrong with conforming to one of the three long hair options when I'm in uniform. My time out of uniform is what I reserve for individuality, creativity, and 'fun' hairstyles. Work is work. I'm told to dress a certain way, and do my hair a certain way, so I do.