Answer to Question 1: Regarding a group of men, The quote "... how bright their frail deeds might have danced in a green bay" refers to the actions of the latter and the little significance they represented in the end for other people, represented with "frail deeds". "Crying" means to tell stories in this case, and by "how bright" these stories "might have danced" the speaker refers to the yearning of these men to have their actions respected and being accounted for; the "green bay" refers to a proper spot to tell stories in, such as underneath a light.
Answer to Question 2: This stanza can be visualized as a crowded and dimly lit place (setting the mood for the characters), where the good men publicly tell their stories, but receive little attention. These men look emaciated, frustrated, and torn by life, yet obstinate that there will come a time when their stories will be heard and be admired, so they endure their plight.