I believe whatever the conditions of the visa are. Why is it so hard to believe that you can stay in a country for a long period as long as you DON'T work there? If you want to spend your own savings or make money from overseas company why would the government care??
If you got a visa to stay 6 months I don't see the issue. If you don't have the right visa you better of with one way ticket to Thailnd and cheap onward bus/train ticket to Malaysia/Cambodia/Laos. They don't care what you do after you 'leave' the country
That's if you're concerned they might change the conditions or cancel it. But there is no reason why they would. It generates money (both from application fees and money spent in the country)
What's the purpose of this post? Trying to predict the future??
I don't understand all the doubts and sceptism about the DTV. The Thai government DO NOT CARE how long you stay in the country and spend your money there as long as you DO NOT WORK there and steal the jobs from locals. It's a CLEVER move, not a silly one!