So everybody is telling me that there can be problems when taking creatine b4 the age of about 18, and im 15. But.....why? would it kill me if i started taking it anyways.(exagerating)

Your body is still growing, and at your age, it is probably doing the most growing right now. I think you'd be better off waiting for a few years and getting a solid diet down first.

No, it won't kill you. But like AJP said, get yer diet down first. I've found most teenagers have horrible diets that when fine tuned more they get a lot better results.

alrite i guess a few more years'll due. But while on nutrition, im 6'0 and 138lbs.(ectomorph bout 6-8% bf). so w/ this info...i know i need to pack on some weight, but how many calories do i need......is like 3000 good, or something like 5000 closer.

Ectomorphs probably need about 4000 calories a day in proteins, carbs, and good fats.

But not everybody is the same, someone can be an ectomorph and be 5 feet tall, and another guy could be 7 feet tall, they wouldnt have the same caloric requirements though.

Creatine is fine, but you should get your training and diet down first to see the full benefits of it.