Oh man, thanks for this thread---having just watched the film, Room 237, and a bit of Ager's videos I gotta chime in.
I went into the film unaware of the nature of Jack's character beyond "he goes crazy!" at the end, which everyone knows due to pop culture osmosis. I recalled him being an alcoholic because I'd seen gifs and references of the bar scene, but I wasn't aware of the physical abuse (self-described as a "one-off incident", but you'll note there's a gap between when it happened and when Jack went sober) but, yeah, I think the film definitely wanted you to get a sexual abuse vibe as well even if it didn't actually happen. The fact Tony "lives in my mouth" for me at least felt very uncomfortable---on the surface level maybe it just references the fact it's a voice, but the way he described it made it feel like a physical object and, well, yeah I think you get the idea.
There's an Ager video where he talks about bear motifs---and though the costumed man in the original novel is a dog, he points out the film exorcises all the additional fluff about that character and thus it can be totally reinterpreted and, in fact, definitely resembles a bear to me. He then points out the framing of the oral sex scene is similar to that of the initial scene where Danny is partially obscured in the bathroom and I do think it's plausible that that's Wendy coming to the realization of the true abuse between the two, or perhaps what she expects. I wonder if the granny scene, also taking place in the bathroom, is also some sort of guilt ridden hallucination by Jack---or, if you subscribe to the idea that he's a victim of abuse as well which was in the original novel iirc and could still work in the film since the whole pattern of abuse, him reliving being taken advantage of by a much older individual.
On a slightly off-topic note, one element I haven't seen any of these essays cover is the choice of Looney Tunes, because I feel like those were purposeful choices---I believe at one point you see one of those Ralph and Sam shorts at the SnowCat shop on television, which seems like a (almost on the nose?) reference to Jack being a wolf (well, coyote, but similar concept) in sheep's clothing (which comes up again with the "three pigs line"), but also probably plays into the idea of Jack being stuck in a time loop. After all, Ralph and Sam are simply doing a job each and every day and clock-out at the end only to resume the next day. But I don't know if Kubrick was aware of that element of the cartoon or simply wanted a wolf-in-sheep's clothing metaphor, but I found it neat regardless.
A Playboy from around the time of filming was used, deep intentions!!!!
But in the context of the scene, as far as I know, there's a mismatch between where and who Jack is (a supposed "family man" in the lobby of an upscale hotel) and what he's reading. Maybe it was different during the time the movie was filmed, but I don't think magazines like that are usually in hotel lobbies.