Without the cards you'll struggle to VIP the guests, meaning they'll ask the questions each time that they return.
Gaining the cards has been made easier with this update, you can no longer not draw one that you need.
Used to get 3 x Myst cards and have to redraw, or reload.
Now, every 3 cards drawn will always contain 1 that you need.
Generally you'll need the Room Item, the Inventory Item (search the attic during the day, there are 14 items in total) & at least 1 x +5% card, higher star customers will require 2 x 5+%.
Sofia requires The Courtesan, to make it 3 x +5% at some VIP levels.
You'll also need to get the Office renovated, as this allows you to add an extra 10%.