I had the exact same thoughts while making it, I usually try and create things in a way that “makes sense” so there is no “mcguffin” answers as to why things work. I was planning to add more chains to the suspension of the chandeliers, so it staying “in place” and not tilting/moving would be more believable, with the fire I was definitely going for a fantasy look, plan was to make the animation of a character entering, moving through the darkness and suddenly - boom - fire everywhere - but my computer with only 16gb of ram decided otherwise, when crashing blender for the milionth time.
I agree with you on it being too dark, It’s probably more of an issue with my textures, as I did them early on in the process before adding the lights, tried to export, it was way too bright, so I quickly dimmed it and let it render for the night hoping for the best. There will be more updates here if anyone cares to look, I plan to polish this one out, mostly retexturing various things, and adding more detailed elements to make it look less empty.