I was taught that coming accross the body on ANY forehand stroke is a bad thing. But then the way I was taught wouldn't work for Carl if he has shoulder problems. My coach starts her students off without adding in the forearm until their stroke is ready for it. The way she explains the stroke, is to just "run". move your arms like you're running. This involves the shoulder quite a bit, but it also makes it almost impossible to cross your body.
Now when looping the stroke is EXACTLY the same, never losing sight of the paddle, which I know most of you are going to go crazy about. We turn our body and transfer weight on every stroke but for a forehand loop we turn our body a bit more, go down on that right knee a LOT more, push off that right leg hard and transfer our body weight.
Also with stance this is going to drive some people crazy, regardless of height she likes to teach players that their Forehand foot's front toe should be halfway down the other foots shoe and then spread the legs. This is contradicting to many people's teaching of the forehand because they all say your stance should be MUCH more open than this. I tend to open up my stance a lot and she doesn't mention it so I think this is just the basics for starting or maybe she just doesn't like how I lose a lot of my body weight transfer when I get back to the way she likes.
Finally: She doesn't like backing off the table, says if you can play close, backing up later will be easy. Looping underspin close to the table is easy, I'm sure most of you agree, but when the next ball comes back fast most players like to back up to do another loop against that topspin. She advocates something called "quickloop" and doesn't like to back off for another loop. This close to the table play could just be because she was a professional woman player in china.