When buying a property with funds from over seas?.

I would suggest doing all of the obvious...i.e.: Review who company, corporation, LLC, Individual, etc. or whomever the investor is. Upon your review, qualify your investors, if you can’t find anything to review, that might be a red-flag. Try speaking with the people on the Phone or a secure internet web-meeting. From my personal experience and just investing 101, if a person or group of potential investors say they are willing to invest large amounts of capital/cash into a fund or whatever it maybe, then if they are indeed a "real" investor they shouldn't have any problem in meeting with you face to face regardless the distance between each person. Keep in mind, it's their money after all so they are going to be very cautious with where and whom they invest it if they are indeed a "real" candidate.

TIME IS THE ANSWER - WAIT 3 -4 weeks to clear the transaction. HAVE YOUR BANK GET INVOLVED WITH THE WIRE TRANSACTION. or L/c.

The only true protection is to not enter into a purchase contract until the money is in the USA. That might be an inconvenience for the buyer (loses 30 days of interest on the money), but we just had a seller scammed by a "funds are in Switzerland" buyer.
If you do enter into a contract, do not give the keys to the buyer before closing. Get huge earnest money that goes hard.