@Advice 5- You have no idea whether he will get a scholarship or not. I am running roughly the same times as him, and I am the same age as him, but I am an extremely late bloomer. My body will still be in developmental stages during my senior year. I could drop my 3200 time by a minute, or I could drop it by 15 seconds. No one can predict an outcome for someone they don't know.
@OP- You should be building mileage at this point, you should be around 40-45 miles per week. Keep going up until 55-65, depending on whether or not your body can handle high mileage. If I were you, towards later July, I'd add in some long runs, and some tempo runs. 10-13 miles for the long runs, and 20 minutes or so for the tempo runs, you can round down to 3 miles, or even up to 4. Run these tempos around 6:05-15. If you maintain your mileage while adding in the key workouts, you'll be in great form for cross country, good luck.