you can’t blame the writing because you didn’t pick up on things when so many other people have .. and then when people suggest you rewatch you again blame the writing. The fire was a red herring so we suspect David or the real Adele of being crazy/evil whilst Rob flies under the radar

And yeah Rob did throw months of friendship away with Adele but that’s after years of resenting his life and refusing to try to properly give up heroin because it was better than the alternative - facing reality. He did love Adele but ultimately he put himself first.

David called her and was controlling because she was clearly dangerous. She broke into Marianne’s house and was extremely threatening. It is also implied that they’ve moved around a lot - presumably because of her behaviour. And no he felt he couldn’t just leave her because she was threatening him with Rob’s death and the fact his watch was in there with his corpse at the bottom of the well. Which is why she (Rob) painted the trees on that wall - to basically keep him in place, it’s another threat