Why do you think it is important to holden that the reader know he was able to peg the three ladies from seattle as tourists? why does he feel like he is humoring them?

It is important to Holden that the reader knows he was able to peg the three ladies from Seattle as tourists because he wants to appear as a savvy character, he wants to show that he is cool and sophisticated, he knows his way around New York and he is not a tourist. He always tries to keep a distance from everybody else. Throughout the trip, he tries to appear as independent, like he is one step ahead from the adult world he criticizes.  Especially because he is extremely critical of the adult world, he thinks the crowd at the bar is phony.  He compares Phoebe's intelligence and maturity to the shallow touristic type of girls he meets at the bar.  He criticizes them because they are so interested in spotting movie stars in the bar, which he thinks is ordinary and shallow.  He feels like he is humoring them because he tries to impress them, he follows their movie star interest and lies and says he just saw Gary Cooper.

is it multiple

he is. some of his decisions were very irresponsible and did lead to the death of both romeo and juliet, such as him marrying them too quick or him not clarifying romeo's plan with him.

basically he did not think things through well enough or at all.

hope this