@Bill ********
what is imagination 555. Who starting check? Where check ? Who will revoke visa and how ?
#1 immigration office even don't have information about your DTV Soft power course as long as you not provide it all by yourself
#2 for immigration you can reschedule your course as long as you not attending yet there is no problem as long as you follow the rules of education organisation or company where you have your course
#3 MuayThai or Thai cooking don't have to report anything to Ministry of education and Immigration office so any reference to ED VISA it's not the same
#5 immigration can not revoke any visa issued from Thai embassy ( only Thai embassy can do it but they not going to go to check Schools of MuayThai and Thai Cooking inside Thailand which is now enormous big amounts of organisations )