I think that means other dialects in China. You know, other than Mandarin, like Cantonese or something. Hope this answers your question. :)

Well, I think there is no big difference between these two when you try to use them as adjective meaning the best. Context is more important. 最好 is more like a statement, a matter of fact. e.g. 我们公司的焊接技术是整个城市里最好的。If you want to cheer athletes up in a competition or convey your proud for the country, it will sound too smug or arrogant, though maybe sometime it is true. And, yeah, if you use this word before a verb, it can mean "had better do something", but it's not the case here. 最棒 is more informal and emotional. I think it conveys the idea that hope we are the best or I think that we're the best. But if you use 最好，it's more like "you know I'm the best." So, hope this answers your question. Also, it should be 中国是最棒的. Don't forget the 的, the sign of adjective~

你姓什么？&您贵姓？—— People will just answer you their last name. e.g. 我姓张/免贵姓张 你叫什么（名字）？& 你的中文名字叫什么？—— People will answer their full name, not only first name. 请问怎么称呼？/应该如何称呼您？—— What should I call(address?) you? Formal and polite. Used a lot. 请问阁下是？—— Normally not used in real life, but in some literature. A little bit Shakespeare. Generally, we don't ask people for their nick name. If they'd like to use nick name, they'll tell you so don't worry. But we do have a tendency to use something like 小张、老王, especially in working relationship. You can regard this as some kind of nick name. If the people around you use these a lot, feel free to use them, too. Also, if there are three characters in one's name, you can shorten it for the last two, or if there are only two character, save the last one and add 儿. These are normal cases in northern part of China, but I think most southerners prefer the whole name. Sorry that there is only one line really answers your question. _(:з」∠)_

well, it's like you have quick and quickly. We here use 的、得、地 (all three have the same pronunciation 'de') to define if it's an adjective or adverb. 很快地学会——quick is placed before learn, and it's used to describe learn ——choose 地. e.g. 疑惑地问、耐心地解答 学得很快——quick is placed behind learn, and it's used to describe learn —— choose 得 e.g. 这个问题问得很好、写得很漂亮 很快的学习者——quick learner. though quick is already an adjective, we still use 的 after it. and note, it's always a noun (or a phrase functioning like a noun) after this 的. 在中文里一般我们管这种短语叫“定中短语”，即定语修饰中心语，有adj.和n.两个部分，然而我们会把前两种使用‘“得”、“地”的情况，整体看做谓语。 BTW，出于习惯表达，前两种情况并非总能互换。