The real problem is that these judgments are subjective. There are many cases where good people can disagree whether something is even any kind of bigotry or not.
The recent case of a random white man who was accosted by a black woman for wearing dreadlocks is an interesting example. She felt passionately that it was bigoted for a white man to wear a black hairstyle (and many people agree). Many people feel that a hairstyle is a personal choice and that even historically dreadlocks aren't exclusively black.
The same is true for sexual assault. Dan Savage (the famous sex advice columnist and the founder of "It get's better") got in big trouble for saying that it was OK for his boyfriend to initiate sex... even when he was asleep. Many people think that this is sexual assault since you should get affirmative consent each time. On the other hand, many people feel that in a committed relationship, implied consent can exist until revoked.
In any case, these are subjective judgments that people are going to disagree about. I don't think that adding additional layers is going to change this fact.