Don't get too stressed over it. Paint and painters are cheap. If a bodgy paint job is the worst thing that happens, count yer blessings mate. Us farangi do get caught up expecting to get what we pay for. Sometimes it's easier to just shrug yer shoulders, accept it and get on with it yourself. No biggie.
One poster about 6 or 7 years ago lost about 1/2 million baht on a house, paid the initial payment to a big renowned company - they then broke the contract by subbing it out to a local crew of somchais. The contract was broken again by using a shitty type of cement, he showed up out of the blue and caught them. By the time they got to the pilings the whole thing was ruined and couldn't be salvaged, it started falling apart - some dodgy bodge up attempts were made that were laughable. Whole project had to be abandoned and he lost the lot.
Don't stress about the paint if everything else is okay mate.
Thanks for the great thread. Good luck with it all.