For the canonical character from which this one is based, see: Boxey (TOS).
After the then-six yahren old survives the attack on Caprica, he joins the Fleet and suffers the loss of both Muffit and, later, his mother, Serina. During the exodus, his anger and hatred for the Cylons grew even further, the seed of which was planted when the Cylons killed his biological father some yahren earlier.
Troy's drive to become a Colonial Warrior is spurred by his hatred for the Cylons, and, to some extent, his respect for his adoptive father. The result of his drive was his being the youngest Warrior to have graduated from the Academy, which was later a record beaten by Dalton, the daughter of Starbuck and Cassiopeia. After graduating, he is disappointed that they had been able to evade the Cylons, at least for six yahren.
While Troy is angered at Starbuck's death at Ochoa, he is happy that the Cylons have returned, and is able to fulfill his need for revenge.
Prior to Adama's death, he elicits a promise from Troy to dedicate his life to serving the Lords of Kobol, believing that their wisdom is the only way the human race can be saved.
As for relationships with fellow youths, Troy was Dalton's babysitter and language tutor during her childhood. When she becomes the youngest Warrior to graduate Academy at age 17, he comes to recognize that he is romantically attracted to her, despite the eight year age difference (RH: Armageddon).