I've learned a few things since making this post a while back. First, I traveled from MN to Boston with a stick for my son and had no trouble at all getting through security. They treated it very routinely. I went to the airport before traveling and asked about the stick and they said it's fine as long as there is not a hidden sword in it or a spike on it. On the planes, I simply put it in the overhead bin. I was also advised that if I had a window seat, I could keep it next to me.
I made a stick for a friend of my son's who lives in Denmark. He recently traveled home with his stick and had no trouble on an international flight. So I can say that it looks like airports are pretty stick-friendly. You also get lots of interesting looks while walking around with a stick as well as some compliments. Just be careful in crowded places, though. I was holding mine horizontally and turned too quickly, striking a man who was trying to rush past me. He didn't seem pleased.
Regarding shipping, I've been shipping finished and unfinished sticks for my business, and I make my own cardboard "tubes" which are actually triangles. I find long pieces of cardboard and cut them about 16" wide. I score the cardboard so I can fold four 4" lengths to make a triangle, with the fourth section folding over the first. When taped shut, this makes a really nice box for the stick. I've had no trouble so far shipping sticks this way.