I feel like the film addressed most of the things you mentioned above, maybe not directly but certainly in deep layers woven throughout the plot.
The state lines - and the hotel which straddles them - are a metaphor for one of the main themes in the film : duality. The hotel itself has a duality to it's nature; it is literally built over two different states so is subject to laws and regulations of each in their respective zones within the hotel. This duality extends out from the hotel to the characters - one is a robber pretending to be a priest, another a charismatic and seemingly enlightened cult leader who's really just another violent and manipulative antagonist, a seemingly mild-mannered hotel staff member who's actually an experienced Vietnam sniper, a salesman who's actually an FBI agent, etc. Even the seemingly straight-up Darlene is presenting herself as a more polished version than what she is - which we see when she removes her wig.
There's numerous other references - the roulette (red/black), Billy Lee's speech about right and wrong, Father Flynn changing from black clothes to white at the end of the film, time changes back and forth, and more. Essentially the whole film is approaching the angle of not knowing exactly what is what, not until the very end.
Can't say I agree about Hemsworth casting either. Cult leaders have generally not been quiet and ugly types; they're attractive, charismatic, charming and persuasive people who find it easy to make vulnerable and malleable victims not only trust them, but completely believe in everything they preach. Hemsworth ticks all these boxes in this film and it's only at the end when he starts to lose his temper, his control and reveal his true nature that we see who he really is.