Phrases embracing an adverbial clause

A. Singing while others are reading is not a good manner.

B. Dear Ann Landers: I was happy to see your response to "Meat Eater in Connecticut," who was upset because the bridal dinner was vegetarian. As a long-time vegetarian who has prepared countless meals for others, I can tell you it is possible to set out an elegant and satisfying meatless banquet that will please even the carnivores. Meat-eating guests can have their usual preference at every other meal. Why not make this wedding menu an adventure into cuisine they might not otherwise experience?

The bride is entitled to plan her wedding feast as she wishes. It would certainly dim the joy of the occasion to see it celebrated with animal sacrifice. It is important, however, to avoid making the absence of meat so important that it becomes a political statement. Guests should not be made uncomfortable. Many meat-eaters see vegetarianism as a moral judgment on their own dietary choices.

C. The bus being so slow that we were late for work, I think we may as well have taken the subway.

1) In 'A', the gerund with the adverbial clause is used as the subject phrase, so 'A' isn't heard odd and in 'B', the gerund phrase with the adverbial clause is used as the object phrase, so 'B' isn't heard odd, but in 'C', the participle phrase with adverbial clause is used as the adverbial phrase, so 'C' is heard odd for me; am I unusual?
2) Do people use such structures as 'A','B',or 'C' often?