For buying livestock from other reefers, u can just negotiate yr terms n questioning. learn to say no, if u r uncomfortable. U can avoid these unpleasant issues.
As for the zoas, I feel u... But if someone want to sell n there's a buyer who's willing to buy, One can't really put a stop sign in the forum to halt the trade.
I was told some regulars of a lfs always get the cream of crop shipments. They in turn frag n sell. Every trade functions like this everywhere. If one disapproves it, then one can don't support it.
For me, reefing isn't about getting the nicest corals or fishes, but to replicate a natural piece of ocean in a tank, n hopefully see them spawn.