I played Nicely-Nicely in high school. I was overweight, loud and hyper which fit the role well. That's not, however, the only way to play him.
We learn he bets on horses (Fugue for the Tinhorns), helps Nathan organize the games (Oldest Established), gets distracted by food (I was eating my groceries!), feels ambivalent about romance (Guys and Dolls) and can make up a story in a pinch (Sit Down).
Your take on the character will color your performance of the latter two songs. I've seen Nicely's who are cynical and deadpan mocking the romantics and manipulating the church goers. However a positive Nicely can also treat those songs as turning points. "Guys and Dolls" can be sympathetic and "Sit Down Your Rocking the Boat" can go from a tall tale to a moment of revelation about his aimless life. It only matters so much as the show's not about him. Still it offers some fun objectives for the performer to play.
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