It somewhat feels like this is the first arc where the voice actors really need to pull everything out of themselves. Since this is a showbiz series, it's naturally much needed. I watch only a fraction of the amount of anime I used to watch, but especially watching Akane and Arima fence with their thorny words, I can't remember the last time I saw an anime where the VAs needed to go so all out.
Not that I'd have ever wanted Aqua to end up with anyone but Arima, but the balcony scene of Akane promising to even aid with a murder was one where I thought Akane is not suitable for someone in Aqua's position. A girlfriend shouldn't assist Aqua in destroying himself. I'm absolutely sure Arima wouldn't do it, while Akane actually would live up to her words. That's also probably why Aqua wouldn't tell Arima such a thing, knowing how Arima would react. Arima would want Aqua to live for himself, for his own future (and her future, if they were a couple), but apparently Akane wouldn't mind Aqua choosing to throw away his life for an already dead person's sake, if that's what he says he wants to do.
But then again, the girls are just teenagers and Aqua is a disturbed man bound to his cursed past.