"Anyone have any insights? I would think coins would be harder to fake than bars since they are so small, but I guess evil and genius aren't mutually exclusive."
Coins aren't harder to fake just far more expensive per unit. One makes a tungsten composite blank slightly smaller than the gold coin and coats the remainder of the blank with gold and stamps it. Nothing to it. But, there's a fair amount of work involved and when coins were selling for $300 - $400 an ounce it wasn't worth it. So very few, if any, of the older coins and smaller bars were faked. Not a problem. The fakes in the small coin business were among the collectables which carry a very high premium.
Both your kruggerands and generic 1 oz coins are almost certainly legitimate, particularly if they were bought from a reputable dealer.
Going forward is another matter. Remember, since you seem to have a spiritual side that gold and silver will be of no benefit on the day of God's fury (Ezekiel 7:19)
P.