yes. Many of my customers apply for 6 months on ward and I did ask Embassy by myself as well, I am not sure about another Embassy but I think should be upon the same rules
Muay Thai easier to apply check at your local area that any muay Thai gym or class that you can buy course and attend for minimum 6 months ,
Also you can use any bank account of any country that belongs to you and balance since June should be not less than 500k per months until current date.
Yes when you extend with local immigration and ton of documents and also tax payment as well because you stay longer than 180 days in Thailand , so the best way just traveling one time per year.