It is a good suggestion, but this kind of system needs human to authorize the special FFK tag. Not all Trade Enforcers are 24/7 standby to monitor everyone.

Well, its hard to know who is right and who is wrong. The main point is, The buyer have reason to cancel the item if he/she have some problems like financial. It's true that, most people will FFK during the last minute during the making payments. But what we as a seller do is, collect some small amount as deposits for confirmation. If the buyer FFKed, then the deposit will be forfeited.
From the buyer side, please make double confirmation before deal in order to avoid SCAM or any other TRICKS by some irresponsible sellers.

Yes, the higher the number of trading would makes the buyer/seller matured in trading section. There are some jokers out there, and what TS could do is just ignore them. It is no point to argue with them since they just playing the fool.
For me, usually I am more prefer to deal with previous traders because we know how we dealt before in past so it is much easier to seal the deal. But out there they are some potential traders do have good and responsible attitude too.

Welcome to the trading world, where everything might happens... I do get FFKed so many times. But what I did was, I just learn the lesson and try to improve my service and trading skills from being FFK again.
No need to hack, slash, bang those FFKers... just note them as FFKers and that is enough..