Duuring, about the hair:
While I'm not sure about regulations, judging by period photographs and drawings, very long (like below shoulder-length) hair was very rare. It would also have been much harder to keep looking "presentable" and, as mentioned before, having shorter hair helped keep the critters out. So while long hair isn't the ultimate sign of a farb, it does look much less historical.
And to Odysseus:
First off, you're in Canada right? And are you part of a unit, or are there any in your area that you have considered joining?