They are very complicated, I am not an expert and the law is not even applied.
TIT. Seriously, this is not my field, I know the some police orders and some regulations but IT IS A MESS. Just look at TV and you can understand why people don't understand. Thousands of topics on a subject that should be clearly explained and applied everywhere in each Thai embassy and consulate. It is not.
In some cases, a foreigner OVER 50 y-o without the financial requirements, or under 50 y-o and not married, or under 50 y-o married and not being able to show 40K per month per couple, some creativity could be the only way!!!!!!!!
With money, you can go in Austalia, UK or USA and get a one year multiple entry easily. Without money, 50 y-o, some incomes or financial requirements, it's quite difficult. Maybe you need to try THAIWALEN.COM or become a journalist, if you don't have a medical condition!!!!! Or a perpetual tourist...