What do we learn about Doolittle in Act 5 of Pygmalion?

In Act V, we learn that Henry wrote Ezra D. Wannafeller, founder of Moral Reform Societies worldwide, telling him that Alfred Doolittle, a garbage collector, was "'the most original moralist at present in England.'" Wannafeller died but left in his will "'a share in his predigested Cheese Trust worth three thousand a year on condition that I lecture for his Wannafeller Moral Reform World League as often as they ask me up to six times a year.'" Being an American, Wannafeller did not care about Doolittle's low class existence, so Doolittle immediately became someone of interest to Wannafeller.

Liza's father does not mind the lecturing but it is living a middle class life to which he objects. Now that he has money, he has more relatives, lawyers and doctors, all wanting some of his wealth. He used to get money from anyone he could, but now he is expected to give it out to others. According to Alfred, "'I have to live for others and not for myself: that's middle class morality.'" Doolittle is afraid he will soon become one of Higgins's students requiring betterment through speech, since his new economic status will put him in better social circles.

Mrs. Higgins tells Mr. Doolittle that he does not have to accept his newfound wealth, but he admits that he does not have the strength to turn it down. He already has to dye his hair to keep his job, and he cannot keep working forever. No, he knows he has to accept it at his age.

Professor Higgins feels he has paid Doolittle properly for the ownership of Liza, five pounds. Doolittle is relieved that Higgins still wants Liza because he sees her as one more relative trying to drain him financially.