How are concerns about family central to both Paul and Ouisa’s choices and actions?

When Paul first meets Ouisa and Flan, he claims that Sidney Poitier is his father. Why is the fact that Poitier is an actor symbolically significant?

The Kandinsky painting that revolves above the stage has two sides, one “geometric and somber” and the other “wild and vivid” (3). How does this reflect Paul’s character and Ouisa’s development throughout the play?