An occasional itch is normal, but you may want to do a check for fleas. Also food allergies can cause itchy skin.
I purchase cat grass already grown as I found if I try planting it myself, then they pull it out when the grass is young.
If your kitty likes to scratch carpet, then I would purchase a sturdy cat stand that is made with carpet so he can do his thing with the stand rather than your carpet. My kitties have always prefered carpet. As for training it is best to put the stand where he is around the most. If the stand is put in a corner of a room he doesn't frequent, he may not use it. Everytime he scratches your carpet, pick him up and show him his stand. I actually demonstrate to my fosters kittens and that usually does the trick. Rubbing catnip on it will help too.
The cat love symptoms, well bad news, they don't subside over time, just get stronger
Good luck and we love to see pics of kitties
