The 65k brigade don't actually renew a visa. All they do is apply for an extension of stay. I did it last week. No change from the last eight years I've being doing it. As you were!
Best place to get advice is from your local tax office. Unlike "tax advisors"(who are touting for business), they have no agenda. That's where I went to be advised I don't even need to submit a return
This job ad is for a Thai person. To get a work permit you need a minimum salary of 60k - no-one will pay that when they can get a Thai at half the price
Very rare you'll be asked on arrival. The vetting is usually carried out by the airline when you're checking in. You may (or may not) be denied boarding so best to check with AirAsia