not right. You can get a non immigrant O visa from outside of the country without a Thai bank account. The when you enter the country you can get a Thai bank account. Anyway go to the visa portal and you will see how it works.
because USD is the base currency for conversions. Pretty much all currencies is based on its value compared to the USD. Similar to the same reason that American English is the go to language between most countries.
Yes and no. If you are looking to extend then without doing it you will have problems. But if you leave within the 180 there is no check to ensure you have been following the rules. Bout with that said just do it online. Best to always have the appearance that you always follow the rules. Besides it takes little effort.
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