Interestingly enough, both of the first sentences are correct, because in English, "dance" is both a verb and a noun. "Dance" or "The dance" means "the art of dancing" and suggests a serious interest to me. If someone says "Dance is my hobby" I imagine they take lessons. If someone days "Dancing is my hobby" I imagine they just like to go out and dance. In #2, the two sentences mean something totally different! "I'm bored" means I myself am feeling boredom and want to do something new and interest. "I'm boring" means that you are making someone else feel bored! Almost nobody would say "I'm boring." People who are boring usually don't know it. A "trip" means one specific event with a beginning and end. "I took a trip to The Netherlands in the year 2000." "Tourism" actually refers to the custom in the 1800s for wealthy young people in Europe to take "the Grand Tour" of Europe. "Tourism" implies travel for pleasure, travel that is not serious, taking a quick superficial look at "the sights." "Travel" has a wide range of meanings. As opposed to tourism, it suggests a trip with a serious purpose, or a deeper involvement in the life of the country you are visiting. Mark Twain's "A Tramp Abroad" gives a tourist's point of view; but Paul Theroux is a real traveler, not a tourist. "Don't, let me beg you, go with that awful tourist idea that Italy's only a museum of antiquities and art. Love and understand the Italians, for the people are more marvellous than the land."--E. M. Forster

1. "Dance" would tend to refer to the art of the dance. Dancing - or dance - as an art form. The type of dance that is performed for others. If "dancing" is your hobby, it can - and probably does - mean that you enjoy dancing for fun. For example, dancing with friends in clubs. 2. "Bored" means that you are weary of what you are currently involved in. "Boring" means that you are weary to those around you. Boring people cause others to become bored.