You can apply for a 30-day extension on your tourist visa, and an extra 7 days after that. But you probably have enough time to apply for a DTV in a neighboring country, if you act fast.
getting a ‘proper’ tourist visa doesn’t exempt you from getting refused at the border. The only advantage it provides is that it’s holder isn’t restricted to the 2 land border crossings per year.
The "ridiculousness" of the 5 year visa would be taken care of from the top, not by some pencil pusher. That said, Thai consulate employees are notoriously grumpy everywhere.
That should be ok. When performing your border bounce, make sure to have all the required documents: ongoing flight (or bus or train), 20k thb in cash and a hotel booking a few days. This is when they are more likely to check these.