Event Horizon-I loved that movie, and I always thought the vibe was perfect for the abyss. Some deep forgotten layer still ruled by obryliths where things were more elementally apocryphal than most.
As for Far Realms-I don't tend to use it, but I'd essentially treat them as not having alignment in mechanical terms. Of course they're something I view as completely irrational to conventional reality not purely destructive. Thus you'd be as likely to encounter one that was effectively neutral or good as evil, but no matter which you encountered it would be equally nonsensical and insane in nature.
"I always pegged Cthulhu and Azathoth as the warm and snuggly, misunderstood type. Kind of like Barney, or the Care Bears." The Care Bears? Barney? No they're misplaced torture devices from a particularly sadistic level of the abyss.