There's no reason why they can't find talented 18- to 20-year-old actors to play angst-ridden roles. It would make the stories that much more credible as the actors age in the course of the series length.
There is this cool little gizmo called a "Loopz" that creates sounds and beats depending on the user's physical interaction with it. An entity calling themselves The Loopz Band will be performing at Comic-Con.
Unlike virtually all of the other shows on the CW, this one has an uncommonly ambitious storyline as its foundation and characters with so many layers to them it could take years to peel them all away.