I have a one year old Siamese cat that I got/rescued when she about 8 weeks old. She will attack and bite my arms, hands, and feet at random times, especially when I am at my computer trying to get work done. She has a ton of toys (balls, feathers, numerous string toys hanging from various places, mice, etc.). She loves the laser pointer.
I am gone on average 10 hours per day. As soon as I get home I will give her attention and play with her, but she still bites and scratches. I have a spray water bottle that I use along with "NO BITE!" but that hasn't worked. I have never played with her with my hands and told guests the same thing. I don't trim her nails because I was told by a groomer that it will only encourage them to sharpen them by scratching on things.
It is too the point that I am thinking about either getting another cat so she not only has company, but will learn that her biting and scratching isn't fun when it is received, or giving a new home which would break my heart.