I don't have the "advantage" of knowing the backstory to this scene or the writing of it. I try to look at most movies or television shows in the context they're cut, not whatever got them there, I don't think that's fair to any movie. In other words, I try my best not to bring any sort of stuff that's not ON screen into any critical view of the movie. Otherwise, I'd probably not like the Hitchcock movies I do, knowing what an asshole he was to actors in general and women specifically. I read this scene exactly as you did: not that she was a LITERAL child, but that she was immature, and Indy as a mid-20's guy in the late 1920's may have taken some liberties, but not that she was 15. I figured she was like a 19 year old, wide-eyed kid with dreams of finding a husband (as Amy notes, the "career pursuit" for women was not exactly a widespread phenomenon in American culture then), she met a 26 or 27 year old and much worldlier Indiana Jones. They had a brief and technically consensual affair, he broke her heart and her dad never forgave Indy. To me, there's enough on screen to merit that reading, and not enough to convict Indy of being basically Roy Moore.
I had to come in here and get defensive because to me, that scene, from the second his shadow shows up on the wall until "I'm your god damn PARTNER!", is one of the most perfectly executed scenes in modern movies. Maybe besides the shootout part, that scene hits its target exactly, a talky, noiry, sharp back and forth between two sets of two characters. Between INdy and Marian, there's all the backstory (and he absolutely apologizes, he says he's apologized repeatedly, she acknowledges he's apologized repeatedly right after slugging him), there's the set up of Marian as a bad ass, hard boiled pragmatist, smart as fuck because she has the medallion on her and she's holding out for more. THe scene gets even better when Tott arrives and basically shatters the whole thing. The way he says things like "Why don't you tell me where the medallion is, right now?" so softly when he's stoking the fire, and how Marian immediately switches from "We're closed" to "Uh, how about a drink for you and your men?", recognizing instantly that this isn't some run of the mill thug but still not wanting to panic (karen Allen absolutely nails this transition). She says something like "I'm not sure what kind of people you're used to dealing with," to Tott, and he responds with the absolutely CHILLING "Fraulein Ravenwood [without looking]...let me show you what I am used to." Even the capper to the scene, where she tries "Let's be reasonable" in the face of torture, he responds "THe time for that has passed..."
I could literally watch this scene every single day and still find something cool in it. It's even tinged with the classic Indy humor, when he asks her for whiskey, or when she takes a shot from the punctured keg. THe rest of the movie is a perfectly paced action movie, it's like a roller coaster, every scene build to something and then pays off.
I haven't finished this episode yet, but 66 is WAY too low for this movie. I'm with Paul, this is closer to a top 20 movie than 66. It's a better movie (not a more impressive achievement, a better movie) than Fellowship, so that either means Fellowship is too high (my opinion) or this is at least 49. I guess once you get into the top 20 you kind of have to have an "impact" factor, but I liked this better than Apocalypse Now, the General, The Graduate and the super schmaltzy It's a Wonderful Life. Honestly, how is Empire Strikes Back not on here but Star Wars is #13?!?