That's right, once all the words have been discovered there's no point in going back to the crossword. There were supposed to be more, but in the end I chose to update all the old cards when we LVL up rather than create new ones that we'd have to go and find, for the sake of comfort. I understand that it does give a feeling of "lack" though!
As for the change of mini-games, these change with each chapter. With Chapter 3 just around the corner, the current job phase should in turn give way to a new interactive experience with the girls.