Back a few years ago, I worked as the executive director of the Tor Project, where I still do a little bit of volunteer work. I love Tor because it gives people a little bit of the kind of privacy and control over their identity that people enjoy in their everyday life. People seem to think that all of these questions of privacy and identity are new to the Internet, but it's hardly the case.
I grew up as the daughter of a minister in a town of eight thousand in the state of Vermont. I knew everything about privacy, and the lack thereof. Everyone knew my business.
I was a teenager in that same small town. So I know all about maintaining multiple identities in multiple contexts. Everyone "knows" that a minister's daughter is supposed to be a little angel or a little devil as a teen, and I decided at about age twelve, that my mission was to keep everyone guessing. At fifty-two, this mission is still in progress.
The truth is, everyone has multiple identities. You have a different identity to your parents than you do to your boss. You have a different identity to your kids, or your teachers, or your lover(s), or your friends or cousins or people in your religious community. You may have friends who you get wild with, and friends who you go watch scary movies with. Each one has different ideas of who you are, maybe different nicknames, and if you run into two of them at once, it can be awkward.
Any teenage boy who has to deal with his mom and his buddies at the same time knows all about multiple identities. If his name is Horace and his buddies have never heard him called anything but Zach, then have mercy.
Do we sound different when we talk to different people? Of course we do. If I'm talking to my great-niece, I sound a lot different than if I'm talking to a sixty year old mechanical engineer CEO. And of course that's ok. It doesn't make you "inauthentic," or "fake." In fact, if you talked to the CEO like you talk to your niece, you would have a serious problem.
In anthropology, we call this the "register" of the voice. People do this mostly unconsciously as they address different individuals and groups of people. It isn't dishonest or fraudulent. It is appropriate. In fact, it's an indicator of their social skills.
Online life gives us the ability to split off experiments in "registers." We can play with identity. We can go into a crowded gaming environment and ask, "what is it like to be in game full of guys as a female character?" if we are male. We can work on an open source project where no one is worried if you are twelve or sixty, male or female, so long as your code is good, and you're reliable. These experiments with identity don't have to be about sex, when they are about gender, or about "fooling" anyone.
Just don't be creepy.
And certainly, if all you are varying is your name, and you aren't varying anything basic about the person behind the keyboard, then why in the world would anyone ever object?
Ultimately, behavior is it's own test, and good social skills and good will can carry your actions forward online, just as they do in any other social space.
The variance of your online identity should always feel honorable and authentic. Shakespeare said it: "To thine own self be true." Be as solid online as you would offline. As Google would say, "Don't be evil." Do no harm.
Within those guidelines, you should be safe online, and in the company of peers, you will be safe. And when people exhibit bad behavior, deal with them within the community. I think most of us learn this by the time we've spent our first year online. We don't whine. We deal.