Billberg used riding talk with smaug because

He used riddling to talk to Smaug I think because he wanted to stall and waste time as he figured out a plan. He also used riddles to talk to Golem who he clearly was trying to stall to save himself as Golem wanted to kill and eat Bilbo. So it is a reoccurring theme of Bilbo and it makes sense.

d.) then bernice winced as marjorie tossed her own hair over her shoulders and began to twist it slowly into two long blond braids until in her cream-colored negligée she looked like a delicate painting of some saxon princess. fascinated, bernice watched the braids grow. heavy and luxurious they were, moving under the supple fingers like restive snakes—and to bernice remained this relic and the curling iron and a to-morrow full of eyes.

i believe that dan is so anxious because he dose not know what awaits him when he gets there. but i dont know to be honest