I have a multi entry Non-O and I have to leave every 90 days. Not a problem as work takes me outside of Thailand... But I don't need to hand over any extra money when I re-enter... Will never be using Ranong... lol
been in Thailand 20 years. Never been asked to show evidence of my passport or work permit... only shown my driver's licence a few times at police checks. Never had a problem with that either