Thanks for the post. I'll look into the Gemma button.
For the rest of your points:
Specific girls aren't required, though they may vary the scenes you get slightly.
There's no lewd scene tied to meeting Howard or Stacy before the charity event.
To meet them, here are the event chains you need to follow.
Two weeks would be too much. I tried to craft this to be very sandboxy allowing multiple ways to complete. I'm not against adding some form of extender cheat for people who just want more time, though.