Bangkok is one of my favorite places and it is a famous place to visit for all foodies and history lovers. You can see the best places from ancient times with the modern blend of skyscrapers, rich culture and with the cheap shopping spots plus with the amazing and peaceful gardens. It has something for everyone, no matter if you are interested in culture, nightlife or history as I already mentioned, you will definitely find something precious for you. Some of the top attractions in Bangkok are Jim Thompson House, Grand Palace, Wat Pho, Wat Arun, and Chatuchak Weekend Market. And for travel freaks there are numerous other options like fried insects, snake blood, or durian fruit! Now If we talk about next question, would say The places you mentioned in your post are the most popular ones. If you want an estimate about your travel time then, according to my personal experience*at three to five days to see the main destinations of the City. It has so much to enjoy such as the culture and cuisine of Bangkok. Have a great trip!