I would say that is a fair interpretation on how it is, and how it will play out - we have had this before with the two entry rule - and generally people who may come 4 or 5 times in a year for short trips are not likely to get pulled, but as you say it's still the IOs decision - I am currently one of those that fly in regularly, but for generally short stays, and a maximum of two weeks at the most, having previously lived and worked in Thailand for 16 years.
same for me as well, I got stung for £500 for excess luggage month or so back when bringing back marketing materials which to be fair out us way over the weight limit
well my experience over the last 3 decades is different, it's changed a lot, particularly in the last 5 or 6 years with regards to these rules are implemented. I dunno, I am on a plane at least twice a month and that is my personal experience.