This is enough to get you started with threat analysis and risk management. How far you need to go is up to you. When I spoke on this subject recently, a member of the audience asked, "Given my limited budget, how much time can I really afford to spend on this stuff?" My answer was, "Beats me, but I do know that periodically sketching out an attack tree or an ALE or two on a cocktail napkin is better than nothing. You may find that this sort of thing pays for itself." I leave you with the same advice.