Those things you describe are all yes/no questions, so it is not true that there are no yes/no questions in Thai. And what you've described are ways to give (for particular classes of question) answers that mean just the same as "yes" or "no" would for the corresponding questions in English.
It's interesting that English has a category (call it "standard binary questions, answerable with yes or no") that doesn't correspond exactly to anything in Thai. But from what you've said it seems entirely wrong to describe that situation by saying that Thai has no yes/no questions.
It's interesting that English has a category (call it "standard binary questions, answerable with yes or no") that doesn't correspond exactly to anything in Thai. But from what you've said it seems entirely wrong to describe that situation by saying that Thai has no yes/no questions.