yes this is exactly correct. If you were not married when the child was born you must use the Thai court system to become the recognized father legally in Thailand.
As for owning land this may actually be possible depending on the law, which I am not an expert in. Consult with a good attorney and this might be possible. You can probably gift the child money, and if you are a legal guardian of his estate then perhaps you can buy land for him? I don't know it's an interesting question actually I'd love to know more.
yes there are other places that are better than Thailand in some ways. For example, Canada has better snow skiing. But on balance Thailand is the best place in the world. The Thai people are the best people in the world.
Paying attention to your visa and not fucking it up is a basic form of respect you should show to the Thai people.
generally the way the double tax treaties work is that if you are taxed in your home country that tax is a tax credit in Thailand but because the Thai tax brackets are lower you could potentially owe the difference between what was paid in the US and what was owed here. But if you're talking about 800k thb and all of that was taxed in the US and all you would owe at most is the difference between the two you're talking about a very small tax liability. Most people in your situation would simply bring the money in not file the tax return in Thailand and never give it a second thought. The purpose of the changes to the tax regulations are not to draw tax out of retirees living on 20 grand a year USD. Complicating matters is that these new tax changes went into effect at the beginning of this year so nothing has happened because no one has filed their taxes yet and won't until March of 2025. Most retirees will not file a tax return and will never have a problem. But if you are concerned about some ambiguity then you'll be best off consulting a tax professional. I recommend calling Ben at integrity legal
180 days in a calendar year. And if you are a tax resident at most you will be taxed on money you bring into Thailand. And then, only on money that is not protected by whatever double tax treaties your home country has with Thailand.
yes most people just walk in. Note that in bkk you must do your first 90-day in person, and after that if your address does not change, and you fill out your online form EXACTLY as your prior form, you can do it online going forward