I want to understand Demons more intimately. What are they like?

I feel like the lore's depiction of demons is often flat, in the sense that we rarely get to see them outside of battle (understandable given that this is WARhammer, but still), speaking, thinking, or anything civil like that.

Like, if I trapped varying tiers of demon in a big secure room and talked to them.... what would the conversation be like? Can they hold a calm and coherent conversation without spending every microsecond trying to kill or corrupt me? What is their speech like?

What is their inner world? Do they have opinions about things? Do they have preferences? Desires? Objectives? Hobbies? Cultures? A coherent sense of self separate from their god-parent? Memories?

What is life like in the warp? Do they... have homes? Do they sleep? What do they do all day? What is it like in there? Do they talk with other demons? Do they have friends? Can demons from different gods make contact? Making contact implies proximity... are there places in the warp?

Idk, I feel like it's all very vague from what little I've seen.

Help me understand.