I ran track and cross both in high school.

Track: I long jumped around 17 1/2 feet which definitely didn't win any big meets but would have gotten me plenty of 2nd and 3rds at smaller meets had I not broken my pelvis. Anyway, I ran the mile and 800 in track as well. Mile time was around 5:45 which once again didn't win anything big but got 2nds 3rds and 4ths at 3 or 4 team meets. I don't even remember my 800 time. That wasn't really my event.

Cross: My best 3.1 mile time was on a super hilly course and I ran a 19:30 which is messed up because hilly coursed drain you much faster. My average time was around 20 minutes.

My advice if you run a 13 flat the 100 isn't a terrible option for small meets. It won't win most of the time but you never know when you could snag some points for your team. That is if your team isn't loaded with sprinters already. About the throwing, that is all about form. I've seen small guys throw a disc a long way. However, when it comes to shot, if you are a big guy you have an advantage. I'd look into that. Don't get discouraged with shot either, it's tough to pick up.

Another piece of advice, vary your workout and hit all areas of your body. Your chest is important for throwing if you pursue that so make sure to hit that up a couple times a week. Also, I don't see any weight for squats listed here. Start doing squats, they are great for lower body. You should look into doing some workouts with rubber bands as well. I always did one where I put two large rubber bands under my feet and up around my shoulders and crossed them so they were really tight and made my legs want to bend. Then, I would bend and jump as many times and as fast as I could. It's exhausting but it develops explosiveness and that never hurts no matter what you are doing.