1. Which Middle Eastern king took part in an episode of Star Trek Voyager before his accession?
Abdullah II of Jordan was given a non-speaking role in the second-series Star Trek Voyager episode "Investigations" in 1996 during a visit to the USA while he was still crown prince. Since he isn't a member of the Screen Actors' Guild, he wasn't able to take a speaking role in the episode. Among his other interests (skydiving, scuba diving, motorcyle racing), he's also a Trekkie, a relatively safe interest compared with the others.
2. Which Asian ruler was reputed to have used his Rolls Royces to haul garbage, and why?
This story is probably apocryphal because it's told in different forms about different Indian rulers and there don't seem to be any photos available. Maharaja Bhupinder Singh of Patiala (also sometimes identified as the Maharaja of Punjab) is said to have been offended by being snubbed by a Rolls Royce salesman, and retaliated by sending some of the older Rolls Royces in his fleet to haul garbage and dung in Patiala City; he never bought any Rolls Royces again, opting for the less snobby American cars. The Maharaja of Bharatpur reputedly registered his displeasure with the Rolls Royce company for slow response to a request for mechanics by threatening to convert the entire fleet to garbage carriers. Maharaja Jai Singh of Alwar, a generally fairly unpleasant piece of work who ended up being exiled from his state after constant complaints about his profligacy and sadism, was also reported to have taken offence at the attitude of a Rolls Royce salesman who didn't recognise him and acted as though he wouldn't be able to afford their cars, bought several cars, and shipped them home for use as garbage trucks. The same story is told about the Nizam of Hyderabad (aka the world's richest man), Osman Ali Khan.
3. Which Asian king married four sisters on the same day? (Hint: his son has recently become engaged to one woman.)
In 1979, Jigme Singye Wangchuck, father of the present king, privately married four sisters, Ashi Dorji Wangmo, Ashi Tshering Pem, Ashi Tshering Yangdon, and Ashi Sangay Choden, daughters of Yab Ugyen Dorji of the Shabdrung lineage (in other words, a descendant of the founder of Bhutan). The marriages were not celebrated publicly until 31 October 1988. They have five sons and five daughters between them. The present king, Jigme Khesar Namgyel Wangchuck, is the son of the third wife, and recently announced his engagement to Jetsun Pema. See a photo of bridal
4. Which Asian ruler used to be a ballet dancer in Czechoslovakia?
King Norodom Sihamoni of Cambodia was a ballet dancer, teacher, and choreographer in Paris before returning to Cambodia in 2004 to become king after his father's abdication. As a child he studied dance and music at the National Conservatory and the Academy of Musical Art in Prague, Czechoslovakia, where he was sent for his education. He studied cinematography in North Korea in the 1970s, and returned home to Cambodia shortly after the Khmer Rouge takeover, when he was put under house arrest with several other family members. After the Vietnamese invasion in 1979 he moved to Paris, where he was professor of classical dance at the Marius Petipa Conservatory and started his own dance troupe, Ballet Deva. He also worked as a cultural delegate for UNESCO during his time in Paris, and was President of the Khmer Dance Association. His half-sister Princess Norodom Bopha Devi is also a trained ballet dancer as well as a Khmer classical dancer.
5. Hanwant Singh, Maharaja of Jodhpur, was an accomplished polo player, like several other Indian princes. However, he had another hobby that was unique to him. What was it?
He was a talented amateur magician. At one point he was invited to give a display of his talents to a large group of magicians in London, and according to Ann Morrow's book "Highness: the Maharajas of India," he was admitted to the Magic Circle as a result of his performance. He was one of the more progressive Indian rulers, handling the transition to independence with more success than many others and getting involved in the political system. He was unfortunately killed in a plane crash during the elections (which he would have won), at the age of only 28.