So, I'm guessing your main character isn't black? Because she'd be way more prominent than Q. I'm also completely confused by how Q being black is racist? And keep in mind your only seeing the demo. So Q and the bard (Who is a mini-route) and the main character are likely not the only black characters in this game.
For the record I clicked on this post because I actually like Q a lot and find him to be one of the more interesting characters. He seems to be extremely vigilant and serious and I'm excited to learn more about him as the story progresses. He's a great counterpart to his partner who seems to be the comedic relief and is somewhat of a clown. ...Like the friendly version of Terian who is also somewhat of a clown. MY hope is that we get a closer look at all these side-characters and not just the LIs. And no. I don't want them to rewrite his character. I'd rather just have them change his skin color if it bothers you or anyone else that much. He's interesting just as he's written.