Edward would be encouraged to marry ASAP to ensure the succession. Possibly Lady Rosemary What's-her-face (the one George V disapproved of because of a relative who drank too heavily and threatened to become a British Billy Carter, if she became Princess of Wales), possibly a Dutch princess if there's one the right age. Edward would still have multiple mistresses, one of whom would eventually be Wallis Simpson. Possibly his lack of morals would have led to a lack of respect for the crown, and more power to the pro-republic movement.
As to WWI and the Russian Revolution, would he have fought harder, being young, eager, and stupid? Would he have argued more fiercely for his cousin the tsar to be allowed to come to England in exile?