I want to call your attention to something. I just want you to notice that it is there. As written, and as I rewrote it, the sentence joins three difference senses of the same word, "live." "Lives in Thailand" combines the meanings of "to be alive, not dead" and "to reside." "Bhumibol Adulyadej lives at Chitralada Palace." "Lives in the hearts of the people" means "to inspire permanent affection that will remain in peoples' memory." This creates a slightly feeling of surprise in the listener, almost like a joke or play on words. This is not a mistake if it was intentional. If it were spoken aloud, in a formal speech, it would work quite well. It would be a good "rhetorical flourish." Another example of the same piece of rhetoric would be: "He drank in the splendor of the landscape along with his morning coffee." In some kinds of plain, factual, expository writing, it might feel like "lack of parallelism," a fault in style. I would leave it in because it works well here. I just wanted to be sure you notice it.

I'm not sure of your meaning. I assume that you are praising one, specific king, the current king of Thailand. This could, for example, the be last line of a speech praising the current king. 1) "the good king is not only exist" is incorrect. "is" should be "does." However, we need to make another changes. You are making a statement about good kings in general, so we should use the plural. 2) Although you often see it, according to the dictionary "fairytales" is incorrect. It should be written as "fairy tales," two separate words. So: "I think that good kings do not only exist in fairy tales..." The smallest possible change I can make to your sentence is: "I think that good kings do not only exist in fairy tales, but also in the real world--in Thailand, and in the hearts of the people." Now I'm going to rewrite it, for style and wording. Different writers would have different ideas. This not a correction; it is (hopefully!) an improvement. I would personally write this as two sentences. "Good kings exist in the the real world, not only in fairy tales. One of them lives today, in Thailand and in the hearts of the people."

I might say , Good kings don't just live in fairytales. They can also exist in real life like in Thailand and in the hearts of Thai people.