This forum has gone full Canadian.

Can I just step in for a second and say I didn't even pay attention to this highly-debated drawing when I watched the episode?

I'm thinking there's some overthinking involved here. Not that it's a bad thing; I love healthy debates, as long as they do stay healthy (and I sense that the current debate might need to stop here in order to be kept that way).

I just realized there's only one episode left. Holy shit. If the show delivers, it's gonna be one hell of an hour.

This is something I've observed too: the way I see the two characters has changed a lot since the beginning. Marty was the slower-witted, down to earth counterpart to Rust. But he's collapsing. The beginning would have us believe this was a good cop/bad cop partnership, but it's now looking like the both roles have switched.

I watched the sequence at the grandpa's house again but no hint really came up. He does say "I've seen kids today, all in black, wearing makeup, shit on their faces. Everything's sex." at some point, but it's probably just foreshadowing (or it's nothing at all).

This is one of these shows where every detail is so carefully thought, I could easily end up over-interpreting everything.

I'm a bit like your friend, except I can acknowledge when something's not a spoiler. Still, I like to hear as little as I can about a movie or TV show if I am to watch it. I want the story itself to show me everything, in its own time and manner.

There's something more to the interviews, I think. I get the feeling that the two cops are trying to understand the characters of Rust and Marty. Their mission might not be only to get material for the current crime investigation, but also to find out about the blurriest parts of what happened in 1995, and everything around it. They're particularly interested in Rust - his past, and what made him turn into the drunkard he is now. They ask themselves, several times, about Rust's relationship with his father. Marty's relationships don't seem irrelevant to them, either. It's a global thing.

We have a thread like that on another forum. It's great to give ideas to people who like spending money. Make sure you attach an Amazon link when relevant.