even stay 180 day "consecutive" may be problematic , the under rule is more about less than 60 days in the last 90 days ( some people get deny entry after 60 day and 1 week vietnam and comeback )
residency and permanent residency is not the same. Staying more than 6 month in Thailand make you Thailand resident. ( that does not mean you can stay forever ;) or give you any specific right )
You don't realy need to buy ticket, you can give flight number.
Personally I fill "to book" in the flight number, meaning I will book ticket after I get the visa... I get the visa no problem and book ticket same day š
yes, a lot of people go without interrogation or problem, we speak about maybe less than 5%. Just read the people who get interrogated to understand what about immigration is looking up.