If you think you're only finding arseholes everywhere and anywhere you go, its worth asking yourself; what's the one, single common denominator in all these encounters?
Also, on previous threads, there have been reports of people, after being denied entry (even when they are blatantly and obviously genuine tourists), and after walking away from the immigration booth, having some variation of the following happen to them:
A local Cambodian or two approaches, asks "How are you today, Sir? Oh, you got rejected? No problem! Give us X amount of money, and we can get you through tomorrow!".
It really does appear as though these local ganger types and the Poi Pet immigration officers have a lucrative little scam going, and if its ever going to end, it certainly won't during high season.
So you've been here for almost a whole year on tourist visas and border bounces.
Best of luck, but with that level of consecutive short-term stays, its extremely likely you *will* be questioned when trying to get back in.
All we really have for you is 1) Have the Three Proofs of accommodation, cash, and onward travel ticket, and 2) Be *very* careful about which airport you choose.
Correct me if I'm wrong, but I'm pretty sure METVs from the embassy in Laos are only available to Laos nationals, or those with permanent residence in Laos