@Christopher **********
I also read stories of DTV approved very easily, and I also see a lot of people here are trying to get this visa without a real reason.
It would be very logical when you only could get this visa when you need to be over 3 months in Thailand.
If you cannot prove that, you might be lucky to get approval, but you also should not be surpised when you got rejected.
When you have more than one reason to be in Thailand for longer time, you should apply for the reason with the longest time.
Please try to imagine what an officer processing your application will think about changing reason after rejected for a certain option. How credible this will look? Just trying options until you are lucky shows you not really need the visa for the reasons you mention.