For question two, Malachi could increase the intensity of some of the workouts, while also increasing the amount of time he does them for.
For question 3, Malachi’s workout plan is very specific in his walk/jog plan. As he aims for a specific heart rate for a certain amount of time, many times a week.
For question 4, Malachi could use the overload principle by continuously increasing amount of time, and intensity of his cardio. Making it so that he has to do it for longer and harder. Increasing his cardio respiratory endurance.
For question 5, If Malachi switched to muscle gaining, he would do less of the cardio and move of the lower and upper body resistance training, along with a-lot of heavy lifting, with eating lots of protein, fiber, and carbs.