What does Hamlet's expression of concern about the child actors used in the city contribute to the plot or to the development of his character?

Answer 1

It advances neither plot or character a jot. It is only fair to point out that this particular passage occurs only in the Folio text and is not in the Second Quarto. Perhaps it was an insert intended to comment on the relaxation in 1600 of the ban, placed in 1590, on boy acting companies, who were putting a cramp on the income of the adult actors. As it was only a piece of topical comment, it didn't find its way into the Second Quarto but did into the Folio somehow.

Some might say that this passage shows that Hamlet is artistic but surely his "advice to the players" shows this much more convincingly. He is just bantering with Rosencrantz and Guildenstern until he can find out what they are up to. Shakespeare clearly used this banter as an opportunity to take a poke at the boy actors of St. Paul's and others.