- While this isn't a point for or against it, there is a moment at the beginning of chapter 2 where Sara is bleeding after breaking a mirror while beset by hallucinations. While this would normally be a point against her being a doll, it's important to note the whole sequence is a nightmare, and we do not definitively see her bleed as of yet, leaving the possibility of being a doll open.
Onto Miley herself, though. Sure, she plays the part of a complete reveling sadist, but her "smiling doll" moniker has already been shown to be some degree of a thematically-enforced "Smiling Doll" theme. Even if it does turn out that she's cruel, however, she has clearly acted in ways against the interests of the game. She told Shin Tsukimi about exactly why he was guaranteed to die, as a result giving him a chance to survive. When speaking to an unseen party on the first floor, she claims that Gashu is going to destroy the Main Game, a fact which couldn't be further from the truth - he's literally loyal enough to its completion unimpeded to cheat and die for it.
She then leaked the victory statistics to Sara, something Gashu was extremely displeased to find out she'd done. Lastly, the Hope Spot throughout 2-2's Main Game was started by her suddenly overriding the screen to tell them Gashu had cheated and interfered with the game in some way. Hell, even when this failed, he shot himself, as a result depriving the kidnappers of one of their implicitly most important members.
- It's possible that Sou learning of the game statistics really was part of his trial, though. The result of him learning that he was most likely to die in the game was to make him hostile and suspicious of everyone, which impeded his ability to work with the group. Sue Miley may have given Sou a "chance" to survive the game, but Chapter 2-2 established pretty clearly that if Sou had been working with the group from the start then the entire group would have had a much better chance at surviving thanks to his hacker skills, meaning that Sue Miley telling Sou about the statistics played into the cruel irony of the game as well as anything else she's done.
- As for the rest of it, Gashu also may have been loyal to the game's completion, but he did break the rules—rigging a card trade to make it almost guaranteed that Nao will die instead of Kanna. Since the game creators' motives aren't revealed yet (the fact that Kai calls the game a "mission" for them probably means that the rules really are important enough to justify Sue Miley stopping the game) that may well have been a violation worth interrupting the game for. Likewise giving Sara the statistics may have been displeasing to Gashu because it meant they would be able to use it to figure out his rule violation, not because it was actually bad for the game.
- Gin's surname, Ibushi, is written with the kanji for 'Boiled rice' and 'Cover'; while different kanji are used, it also sounds like the Japanese verb for 'Fumigation' — burning out with smoke. (The same verb can also mean 'Torment', for extra fun symbolism.)
- Q-Tarou's full name is a pun on not just hamburgers, but BBQ.
- Keiji's surname, Shinogi, is 'Bamboo grass' and 'Tree/Wood'. It also happens to sound like the Han character for 'stove' or 'bright'... and as noted above, Chapter 2-2 suggests some troubling parallels with the past.
In all likelihood, somebody here is going to burn. And lucky us, we're probably going to get to choose who.