If you research plant genetics you will realize that most of this is speculation. Your plant is pre-determined to be male or female by the genes in the seed. This is also why you always get females by taking clones from female plants. They keep their genetics.
Stress factors along the line may make a herm but will not change the sex either way.
Unless there are very specific exceptions to this and marijuana falls in to that category, light schedule will not influence the sex of your plant
Dont believe someone's stats unless they have done a scientific experiement with at least 50 control and 50 experimental specimens. To date I havent seen anything close to this