I'm far from an expert but I've never heard of that. I've seen several girls at the meets with their hair ponytails or braids, etc. I find it hard to believe that so many coaches would take such easily-rectified deductions.
I've seen an entire team come for a meet with all the hair done in 2 long braided ponytails. They obviously touch the back of the leo(if not the front too!). I've never heard of a deduction for that. I have heard coaches tell kids of these "unheard of" deductions regarding hair so their kids will show up with very neat styles and no hair hanging down etc.
I've never heard that. They can take a .1 uniform deduction off the AA but I've never seen it for hair. Usually it is for undies or bra showing. Even then, I have never seen that deduction. The chief judge has to warn the coach before taking the deducation. I know that really long hair flowing about can be very distracting, tho.