Advice for violent baby?

My 8 month old is violent! Lol, I'm kidding, sort of... I need some advice on teaching him to be more gentle. He's so high spirited and active. He's already pulling himself up on things and cruising and he's into everything, he wants to touch and explore everything he can.

However he can get too agressive. Like he pinches. I know he's mastering that pincher grasp but how do I get him to stop mastering it on the backs of my arms when I'm holding him or my breast when he's nursing. He also likes to grab faces and claw and pull at lips, noses, eyes, ears... And he smacks a lot too.

I know at 8 months, he doesn't really understand much. I try to tell him to be gentle and I stroke the back of his hand and arm and say gentle, hoping he connects the word with soft touching eventually. But for now, if I try putting him down he cries and doesn't understand why mommy doesn't want him. Then as soon as I pick him up again, pinching pulling hitting begins again. Lol.

Is this a short lived phase because I've had 3 other kids and I don't remember being abused quite this much in the past? :-)

how did you teach your baby to be more gentle?