Aqua totally likes Arima. He actively did stuff last season just to keep being able to talk to her.

As for Aqua's perk, it's his time working in post production that allows him to gauge what performances work. His acting takes into account the camera angle, lighting, spacial awareness etc to make it more effective than raw acting skills alone.

Whether that's good enough to keep up with prodigy people though is another matter. I am curious about this as well since they set things up like everyone is a gunner.