It's worrisome that people use one's name to judge and conclude that one is a bad character. In my continent; Africa...
Seeing you mention Africa, instantly my instincts told me you were from Nigeria before I went ahead to read the parts where you mentioned in quotes some users from our local board. My instincts was from the recent happenings in the country and the security challenges where several atrocities have been attributed to unknowngunmen – UGM – for short. I reasoned anyone who could come up with such username won't be far from being a Nigerian. I'm right, then.
About the-not-so-good experience you said you had upon you entry in the local board and how your moniker allegedly sounded a wrong bell, don't take such experience to heart. I believe those brethren there were just catching cruise and didn't mean anything sinister. Usernames aren't to be taken seriously, anyway.
I have heard stories about children bearing good names such as John, Moses, David, Jacob, Joseph etc involving in robbery and rape cases and all sorts of vices.
That reminds me of what I learnt in school years ago – What's in a name? There's another that posited that nothing has a meaning except that which we posited it to mean. By the way what makes you think those names are good names? Come to think of it, those names were mere common Jewish names, not christian names. They're absolutely not!