Yes, roleplaying is about playing out your fantasies, but there's a limit to what most people would believe. I'm not saying a 12 year old anime girl in space (example, not individual oriented) isn't belivable, it's certainly less credible than a battle scarred veteran trying to make a living in a harsh Sirius. I'm sure you can come up with a reasonable explanation for your out of place character, it'd just seem forced and it'd give me a sense of you just twisting the lore and facts in order to suit your role.
If you enjoy playing a certain controversial role then, by all means, continue. But if people tell you that you keep asserting/forcing your roleplay upon them and they don't like it then you're obviously doing something wrong. Play for not only the enjoyment of yourself, but also consider the impact you might have on others around you.