Not many flights buddy. I'm not going to list all international flights landing in Chiang Mai. Suffice to say it's a tiny number compared to even Don Muang Airport let alone Suvarnabhumi.
I suspect it's the previous immigration history / nationality causing the issues and maybe...those who spend the entire 180 days and return same day.
Those like me who usually spend under 90 days per entry and then travel abroad for days to weeks on business and for other reasons shouldn't have an issue.
If, it proves that even people like me start facing issues I'll immediately switch to another visa type and tell everyone not to apply for the DTV.
That's not the proper analogy. Yes, each entry is 180 days but you can come and go over 5 years. You don't need to spend 3-6 months outside the country between longer stays as you do if you're on a 10 year tourist/business visa for the USA. With one of those, you can stay 180 days per entry but assuming you've spent 180 days, you better leave for a bare minimum of 180 days before returning and preferably at least 1 year or you could be denied re-entry.
Thailand allows you to come back the same day or certainly within a couple of days of exiting and do this across 5 years.
Correct. It's similar to a tourist visa but still a separate category. It does not grant you any more rights than a tourist visa does except for a longer stay.
Yes there are flights from there too. You should be OK and in your case makes more sense to fly direct than transit in BKK though you do have far more flight options to Bangkok than CnX