How can I do a border run to Laos from Pattaya for a new DTV stamp, and are there trusted agencies in Bangkok?

You had a "wild flight"? Sounds like a turbulent flight? Just the way it is....it's rainy season and it will be bumpy. You might experience what I did a couple of years ago, while flying towards Bangkok out of Singapore on SIA - flying through a thunderstorm and dropping probably a couple of dozen feet. It is what it is. Can't be avoided. It's the reality of air travel.

If you're afraid of flying - wait until late October or later, which is when the air becomes calmer as the rainy season comes to an end, though anywhere south of Samui will experience a second monsoon.

Or just travel by land. Other than Cambodia and most of the Burmese borders, the rest of the region remains open. Laos and Malaysia are your best bets.