Anyone else have a baby that pulls hair, pinches and so on...?

My baby is 5 1/2 months old. I know he doesn't hurt me to be mean, but I am so frustrated with the pain. He is just a rough little boy. It is actually really sweet at first; because when he is sooo excited to get picked up he will cling like a little koala bear and smile really big =) But then here come the hands for the hair....and he gets a hard grip. I try to keep my hair up as often as I can, but having my hair up gives me a headache sometimes. I guess I am not used to it. I usually hold his hand so it doesn't hurt so bad and firmly say "Let go of mommy's hair, that hurts mommy!" We are trying not to just say the word "No!" to everything, so this is what I have resorted to.

My son also pinches really hard on the back of my arm. I breastfeed my son and he clamps down real hard sometimes. He doesn't have teeth yet, but I am scared when he does. I do not want to sound like a wimp....but like I said I am frustrated with this.

Has anyone else experienced a rough kiddo? Do you have any suggestions on ways I can encourage him to stop, or at least ways I can work with him so this doesn't become a problem for the future. I have two older children and neither of them did this.

Thanks in advance =)