I've had him for a year or two, and I'll be keeping him for as long as he lives. He was about 2.5 years old and 14-15" when I got him from a fellow MFKer in Ohio, so a total of about 4 years old now. He fed him on only NLS thera +A, and I've continued to do the same.
As for the head scratching, he always put his nuchal hump above the water surface when I was doing water changes, and then he'd splash all over. So I just stuck my hand in there and scratched his head, and it seemed to calm him down. Been doing it ever since. Odd thing is, he won't do it if I'm not doing a water change. It's only during water changes. The rest of the time, he wants food.