Three quick notes.
1) Really love the new design for Arsenal.
2) I changed Arsenal's age to 22 to be closer in age with Superboy and Nightwing, since they were probably closer in age when they formed the Teen Titans.
3) As for side characters I plan on using Lian Harper and Artemis Crock starting out. Other characters that would make sense would be Green Arrow, Black Canary, and the Teen Titans.