I have personally not seen any tire trouble coming from using an LT tire on a trailer...we have even done it before. However, I do prefer using ST tires. Whether it makes a difference or not, I like to believe it is safer as that is what they are made for. As for the ST tires, almost every on of them is made in China. Just stay away from the really really cheap ones and you should be fine. I always like to go up a ply rating when I replace tires too; not so I can overload the trailer but so the tires dont have soo much stress on them.
We have a car trailer and a stock trailer the both currently have 225/75R15 8-ply Akuret brand tires with no trouble (about $60each). On the gooseneck we have 235/85R16 14-ply Carlisle with no trouble either (about $250 each but we are not running tandem duals, just singles).