Hey Dev,
I've been wondering, pushing further that suggestion made previously to pay models huge amounts of cash to do scene types they originally refuse. Basically it would make it even more interesting and plausible, if doing so would push other models to complain. "You paid that bitch 5 million to get gang-banged!?? I do it twice a week, for a lousy 120,000 a year!! Either you level up or I'm gone after my contract ends!" This would make the amount of cash necessary to make such a move higher. It would also make things interesting between models, and add some spice to the game flow.
Ok, even if this suggestion is no good for you, have you ever thought of introducing a competition/jealousy mechanism between models in general? One complains that the other talked trash to her, stole her cocaine, etc. And you have to make a managerial decision. Invite both on your yacht for a luxury weekend, paying very expensive gifts to both, or one of them, to calm them down, etc. Resolving cat fights is a nice fantasy which a lot of players would probably enjoy. Especially when you convince them in making peace with an FFM or FF.
Last but not least how about marrying? I liked that "favourite" option we had. Could push it up a notch. You marry one, even several, Heffner style, and divorce them after a few months, weeks, or even days, if you want, as long as they're ready to sign the papers in exchange for a generous compensation. While married they don't shoot, and might go back to work for a higher pay, etc. Or making scenes with them as your wives, with an bonus "Porn Lord and his married bitch sex tape" to the scene.
Apologies for these brainfarts, but thought it was worth sharing them nonetheless...