Welcome aboard! As for the tribal naming, I'd say it's down to your preference. Inarah, for example, isn't in a tribe anymore yet still has her tribal name and many of her old tribal values and beliefs influence her present behaviour. Whilst she will answer to "J'inarah Marad", she always introduces herself as just "Inarah". I have also met others who don't follow the naming conventions at all and it's not a problem so, really, whatever works for your character and his background should be fine. 
