Some thoughts:
1) Training vs Experience. Right now the only way employees and models level up skills is through training. I think it would be cool if they could raise skills and levels through experience as well. Like a level 1 director shouldn't still be level 1 after making a dozen films, right?
2) Multiple Choice. For the power gamer, I noticed you have a $10,000 fee to change a PA's specialty. What if there was another more expensive option to add specialties? Like pay $100,000 and you can have two specialties... pay $1,000,000 and you can have three going at once.
3) Finance should include investing. Needs an option to increase bank interest rate.
4) A more generalized skill and employment system. This is a big one but please hear me out. When you meet a stranger and ask what they do for a living their response should be what their strongest skill is, but their only skill. So when you hire them you know what they do best but their actual skill list would be all the skills, even if level zero.
Example: Employee Jane Doe, Director 7, Cameraman 2, Writer 1, Editor 1, Helper 1, Set Design 2, Makeup 3, etc.
Now combine that with expanded training and experience and you could have them practice their other skills on the side.
Then we take sex skills and studio skills and apply them to everyone. Just as Ron Jeremy went from doing porn to directing it, an talented porn star could end up applying their knowledge to the other side of the camera as well. You could probably include some kind of bonus for this. This also gives more reason to corrupt your regular staff - level up their sex skills and they'll have a better instinct for movie making.
5) Where did the Lawyer job go? Those were some useful talents in there.
6) Production and Publishing could probably be merged into one PA job.
7) Why does everything lose money? I bought the beauty parlor and it costs money each month - this seems backwards. Buying up side businesses should be profitable. That's the whole point.
8) Human Resources PA to replace Talent PA. You can move that +5 happiness bonus to there, along with the salary reduction perks. They can still scout for talent, of course.
9) The Mansion = Happiness. Simply having a private pool, private beach, private yacht, etc, should give at least a small daily bonus to the happiness of your models. Like +2 for the beach, +3 for the pool, etc. Perks of the job include access to these things, right? All the more reason for models to want to work for you.
10) Reputation = Recruitment Bonus. And once it is known that your models spend their downtime drinking free tikki drinks at your private pool and get free trips to the beauty parlor then finding new recruits should become easier. A big, well established company should be tempting to work for than some no-name start-up, right? Give a bonus to recruitment based on these factors.