Cultural norms do not set the standard for what is right or wrong. Right and wrong --good and evil -- exists and is objectively verifiable regardless of the ability or willingess to acknowledge that reality.
Right and wrong is an objective, not a subjective, concept. It is not relative depending on the society in which you live. The circumstances in which you find yourself are important in determining the right and wrong of a situation, but under the same circumtances an act is either right or wrong regardless of the culture or society in which you live.
It would lead to a better discussion if you would state specific instances in which you think that the same act would be right in one culture and wrong in another culture. I deny that any such circumstances exist, but since you maintain otherwise, then you should give concrete examples so that we can discuss your views based on something other than floating abstractions.
Some cultures are superior to other cultures because they acknowledge the objective reality that certain things are right and certain things are wrong PERIOD.
I think it boils down to more of an acceptable vs. unacceptable comparrison than a right vs. wrong. Yes certain things are right and wrong.
I also suspect that the list of universal 'right and wrong' is a short list.
Western culture looks upon 'arrainged marriages' and teenage brides as wrong because we believe in the freedom of choice and association when it comes to marriage. Yet it is perfectly normal, acceptable, and perceived as 'right' in the cultures that practice arrainged marriages and where women are married off at young ages.
Western cultures look down upon and consider "wrong" many of the practices of island people and other 'native' tribes with their practices of body modification. They see it as normal and right.
Is it "wrong" for parents to arrainge the marriage of their children? Is it "wrong" for one to modify their body by piercing, tattooing, other forms of modification?
I say neither are 'wrong', but also neither is an 'accepted' practice of western culture.