I also thought of Arthur, the "once and future king."
The "nickname" would be Art, which is a wonderful thing to be called!
So far as changing your Chinese name, Youtian is indeed a beautiful sounding name with a beautiful meaning, and people won't have much trouble spelling it. People are more used to Asian names now, and it won't set you apart as much as you might think.
Some of my Chinese friends have kept their Chinese names, some use their Chinese name for their middle name. Lin came to America at the age of 12. She chose Kara as her first name, and Lin as her middle name. The only reason she changed it was because Lin is pronounced differently than it is spelled. Her family still calls her Lin.
Sunan kept her name. Frank changed his. Jeff's parent's gave him an American name when they arrived, as did Mosanna's parents (but Mosanna is not an English-language name. It just sounded American to them.)
Wang is a very common name here in Los Angeles. I just looked it up in the telephone book: 250 Wangs are listed for the City of Los Angeles. (The City of Los Angeles is only a small part of the vast area that is referred to as Los Angeles.)
However, if you choose to translate it, King is a fine name.
For many, it is a part of the process of becoming American to change your name. My father was Waldo Dario Mario Cassaretto when he arrived in America in 1930. By the time he died, he was Oz Glover. It happened through marriage (his mother remarried), and through the other children giving him friendly nicknames, because Waldo sounded foreign to them (remember, this was a long time ago. "Foreign" isn't really an issue these days. It doesn't matter much to people any more.)
Keeping your Chinese name and using a nickname is also good. My father never changed his name legally from Waldo to Oz. His last name was changed from Cassaretto to Glover because his mother's second husband adopted him.
Sorry to go on so long!
