My suggestion is regarding the In-game trade feature. At the moment when both sides click "trade" the trade is done instantly which leaves a window for a lot of scams made by changing the items/gold being traded in the last second (nearly everyone has been scammed at least once).
This can be evaded if time is added when both players click "trade" the trade window freezes in that way for 2-3 sec to reassure that any changes havent been made.So both sides would have some seconds to check the stuff being traded and if anything is wrong they can manually uncheck "trade" within the given time.
I have seen this way of trading in other servers and it absolutely elimantes any chance of trade scamming.I doubt its anything too complicated or time-consuming to add to the gameplay and it will dramatically reduce the number of scams being made.
P.S : Lets not forget that scammers are getting more and more createfull. I have read some complaints from people that claim the scam happened with the help of scripts for changing the traded items/gold. This can happen to anyone and it is not refunded by any way.