So you want to apply in 1 year. Do your research when you want to apply then your information will be current. You need to choose the best option given your situation but Muay Thai would be easy for you. You can apply for DTV anytime why you want to wait.
Applicants don't stick to the criteria as asked by the embassy. They try to put more documents because their portfolio is not high standard. This leads embassy to believe they are not what they say they are. So ask more docs or reject. Follow the rules it's a 5 year visa not for fun do visa exempt if you don't have solid application
Border bounce for DTV is every 180 days = 6 months or just before. I fly out and back stay 2 or 3 nights small holiday . Go where you want but you can take your cat if you drive your car and cross. It's what is closer or more convenient for you. Maybe others have done crossing in one day
You need to leave and apply for a non b in Thai embassy. You work needs to give you the paperwork you apply non b 3 months when you come back your employer the applies for 9 month extension in Thailand local immagration followed by your work permit at labour dept