Buy it from the country you spend most time at. I had one bought in Europe and in Thailand they refused to change the battery since it was not bought from Asia :)
They have no way to collect the fine, unless you visit them and on DTV you dont have to visit them for over 5 years. Even if they keep any records, long therm visas are taken out of the country anyway, so this fine even if its enforced to be paid will be after many, many years and its not sure if its going to be on the record anyway. So bothering with it on DTV is waste of time in my eyes.
its not possible, maximum for this is 2k baht even if you dont report for decades ... And its only if you go to immigrations, while you are with DTV, you dont have to go there, just bounce out and back in...
most of the ppl with DTV dont go anyway, because its easier just to bounce out. So basically for those 5 years you wont have any encounter with immigrations at all to make you pay it.