Things are going well. Nothing ended up happening with the ex (he never even mentioned the note again to her), so we pretty much concluded that he must have written it while drunk or very angry, or some combination of both.
As for the living situation, my father and I helped her move out yesterday while her ex was at work, to avoid any unnecessary confrontation. She is now living with her mom, and things are starting to look up.
He will finally be able to start getting over her, which was impossible with her still living there. She is finally out of that situation and will be able to focus on her own life. And now I don't have the worries of her living with a potentially unstable drunk/stoner.
As for our relationship, things are going smoothly, and I am hopeful that things will continue along this path.
Glad to hear it, Incman.