My cats food & toilet routines .. is it normal?

It sounds to me like you are taking wonderful care of your little guy, and he sounds fine. Not all cats have the same appetite. As long as he doesn't completely stop peeing and pooping, or eating, and is not showing any signs of illness, like crying when he pees or lethargy, I don't think you have anything to worry about. I have found that my orange tabby Lilly ate much less food when she was by herself and more when she had Kitty Kitty for competition!