You guys need to remind yourself too, that it is dressing up. The normal city will stare at you for wearing something that's not bought at JC Penny. Kimonos, costume, lolita, and add the wig, and you're just begging to be awed at. Add in girls in skirts of any length that might or might not add color to the dreary place, and you will get guys looking at you. Anything that is form-fitting, pants and a blouse, or hangs and leaves something to be desired, a nice long dress, you will be looked at by everyone. That's probably... at least half the point of cosplaying, is to be looked at.
There are characters who I think really question our "family friendly" idea, top of my head is Yoko from Gurren Lagaan. I've seen them around before and they look awsome- are awsome "Yoko". On the flip side, that's A a lot of cleavage and B a lot of skin on the legs. That's just the way Yoko is. *shrug*
Even if you're wearing normal clothes and hair for a costume, you'll be looked at at some point in time. I stare at people in platform shoes, or in shoes that don't match their costumes. Or in long wigs that might be tangling. Lots of skin catches my eye if that person is walking by me. Human eye just follows skin. Turn this attribute to kids four feet and under, and I don't think you want them seeing your rump, or having parents complain to staff to ask you to cover up. It's happened to guys. I know a guy cosplaying Rocklee a few years ago at Kumori, at this hotel we're going at, was asked via parent via staff to cover up his manly bits. Clarification: they were covered, but you could see a very ghostly hint of their shape. The guy was cool about it and had no problem with covering it, or modifying it in some manner.
Point is there will always be some parent or person unhappy with your personal private bits being exposed to their 6 year old. How you handle it matters. Skin colored spandex or briefs... Something should cover you.
I really agree with the blanket or towel idea for chairs. I don't like to sit on them just cause the metal around them is cold and makes me more cold when I'm in a miniskirt. Add to fact that I'll sit on the floor a lot at cons, I want a jacket or something to sit on or cover a good portion of my legs. Arms I don't care about. I like my arms and I don't have a bust for people to gawk at usually. One of my friends in pants and a shirt, normal clothes, was gawked at by a drunk guy one con (like he stumbled into us with perverted motives in mind, we could tell), and it was because she's about 5'2" with a huge rack.
Again, we have these creepy people out there. Cosplays are made to be looked at. And sadly, you need to take action to protect yourself. Travel in groups of 3 or more, have cellphones on everyone, and be sure you can sprint or run in your shoes. Not saying you'll ever need that safety net, but it's better to have it than to not.