Meet Sebastian!

I shall now introduce you to another character of mine: Sebastian Joseph Williams.
Sebastian is fourteen years old, and in tenth grade. He is very smart and typically goes to summer school to get ahead on high-school credits. He is doing pre-calculus as a sophomore. His dad has an important position in a successful software company, and as a result is often traveling. Sebastian has a nanny named Leah.
Sebastian's first cousin Antonio lives with him. Sebastian's mother (who died in a car accident when he was eight) and Antonio's father are brother and sister. They are from an Italian family, and Antonio's father married an Italian lady he met on a vacation in Italy. Antonio's parents are in show-biz and travel all over Europe. When Antonio was eleven his parents sent him to the states to live with Sebastian's family so he could have an American education and a stable home life.
Sebastian's interests (besides school) include music, reading, running, and photography. His daily routine: he wakes up at 6:30, goes for a run, takes a shower, and goes to school. After school he goes to the local university for some classes, then goes home to do homework. Antonio, who is fluent in Italian, teaches him Italian. After homework he has free time until bed.
Sebastian is short for his age. He has dark-brown wavy hair and blue-gray eyes. He is shy and quiet, and his boisterous cousin often pushes him into things. His favorite time of the year is Christmas, when Antonio's parents and his father are all together for a time to celebrate.
Sebastian's favorite color is gray. (Boring, I know.) His favorite food is grapefruit and his favorite drink is almond milk. He eats a lot of fruit and nuts. (Antonio thinks he's weird not to love meat.) He is really good at making delicious smoothies, and sometimes makes dessert after dinner. He wants to get a job at a bakery or coffee shop.
I think that's everything! It's hard to tell, because Sebastian is a very real person in my mind. Tell my if I missed any important information!