Is "guy" a disrespectful word?

Sometimes I face this issue in writing. I might be talking about a woman, but she's referred to as a girl often. It's a form of address that we're all familiar with though. Just remember that females mature faster than males, so while a boy is pretty much a boy until he's 18 (and sometimes through college) a girl might be a woman at as early as 12 in terms of physical maturity. My mother said she was pretty much fully grown at 15, and certainly looked older than a lot of those around her. So at what point does one transition into a woman? Also, a 'college girl' might be offended if you call them a 'college woman' which implies they look old. I think in this sense 'girl' is a youthful expression while 'woman' signifies age. It could fall in line with maturity in a different sense as well. An escort would be considered a 'working girl' and an office worker might be called a 'working woman'. In this case the implication is in terms of respect of position. Many other parallels could be made, but it's one of those weird connotations.

I've written a post on how to address each other on myLot. Many members have commented positively on it. This means it expresses not only my thoughts. Maybe you find it of interest.

No, I can't see what's disrespectful about it. It's a casual, informal word but not a disrespectful one. It can be used for both men and women or mixed groups, for example a person might enter a room full of friends and call out 'Hi guys!' meaning everyone. Or say something like 'Come on guys, let's go out!'