It depends on where and which class you will teach. Normally, you need a degree to apply for a visa, but it can also be waived in some cases. There are loads of dancing school here, many of them are successful too.
Would a strong Cv and testimonies help towards getting a permit as a teacher?
It won't have an impact on the visa decision from the immigration, because it's your employer who will issue the letter of request (in theory, requesting you as a teacher). but it will have an impact on decision of your future employer for giving you a job of course.
you have to show the letter from the bank insisting that you have this money once you apply for a visa, to prove that you can support yourself or your family while staying in Thailand.
As long as you have 400,000 baht in your account without withdrawing at all for 2 months. It is ok. It is very important that you don’t withdraw it to be less than 400,000 baht because the book bank is checked too.
The ask:thailand community, consisting of multiple Q/A groups with over 100,000 members, powers this platform. It is not an official government resource. Our members actively contribute to this resource, and while we strive for accuracy, we cannot guarantee its complete reliability. Assistance to travelers is provided as a community service.