Does accepting duality lead only to nondual skillfull qualities?

This question can seem contradictory but form my understanding ,duality is inherent in reality and accepting reality in all its dualities leads to more conscious actions. But if the person as a result acquires ONLY positive qualities then isn't this dual and not in accord with nature? Buddhism lays emphasis that qualities like ,jealosy ,hate,pride and anger are unskillful and qualities like love,peace,contenmtent and compassion are. Don't we kill animals and plants to eat ,don't we fight in wars in self defense, these are negative but right actions to take and underlie negative qualities of brutality . Can we cry consciously can we kill consciously ?