As far as the Hollywoob sign and the observatory, if you’re talking about their physical location relative to eachother you can see one from the other.
I just rewatched the finale and while I don’t think I’m fully convinced, I can definitely see where you’re coming from and I like this take. The wrap-up with each character did feel a bit too neat, not like how it would actually go at a wedding(even in bojack’s universe), and each conversation did give off some deathbed vibes, especially Bojack and PC.
I know Reddit hates the unreliable narrator theory for some reason, but it makes sense to me (and brings me a sigh of relief)