Girl's birthdays would be a cool thing to add to the game.
Maybe the new search the web function could get you her birthday based on the creation of the model.
So you find out Faye's birthday is Jan 27th, which starts a mini quest to find out what she wants, buy it from the store (or maybe Aly wants you to make something for her), give it to her on her birthday and have her spend the night (or Amy's boat ride or a ride in the private plane) which would then become repeatable.
The hard thing would be to advance her age so that the Hot Shots answers match.
Jennifer turned 18 just 2 weeks ago, but that date seems to move around.
Also, since Bantry's been on the island for 3 years, his girls are a lot older than ours.
Speaking of Hot Shots, for 3.1, I think that Auto-Win and Auto-Loss should be removed.
They don't initiate anything in the game except a drink or strip.
It would be better to add two more question categories. One Could be called Stats and the other Favorites.
The questions about a girls measurements and age would be placed under Stats.
A girl's favorite color, color to wear, movie, lingerie, shoes, etc. would be placed under Favorites.
No new questions would have to be made up (except for the PC), but it would be much more likely to find out a girl's age since it would be a 1 in 6 chance to get that question (1 in 10 if you add in implants, body type, etc.).
Another way to get a girl's age would be to add the info to the rumors button at meals in the restaurant. There isn't much reason to listen to the girl's conversations about a snake in my toilet, etc., but if you could get more stats or info about Joy, then it would be worth pushing the button. Things which the girl's talk about that are jokey or make less sense now that the game has developed can also be removed.