Survey: Most Thais will go to vote, oppose coup

I didn't notice any margin of error + / - posted in the article. I do think that the majority would still vote for the current government if a vote was held but the numbers in the poll seems a bit tilted in favor of the government.

Try +/- 30% or more, given only a 1000-odd sample size

A correctly weighted polling only needs a sample that size. Globally poll samples that size are often used and are reliable.