I have heard of some who see it as wrong but as Lark said its not universal. I know a couple vegetarian Wiccans and even a vegan one, but its not a rule. Just how you choose to interpret the Rede. I seem to be one of the few Wiccans I know who don't have a tattoo. Everyone who has a tattoo has symbolism to it. Most common being the pentacle, but my covenmate got one of a Athame and another covenmate has a dreamcatcher. In general the tattooes are thought out and symbols are used in them. About piercings, again, not a general thing. I've got a few, and I think all but one of my covenmates have at least one piercing. Do some soul searching and draw your own conclusion if it goes against the Rede.
Some ancient cultures such as Pics and Scottish tribes wore tattoos. I think if it has meaning to you, thats all that matters.
I only would advise caution in getting only tattoos that foster good energy, they are for life, after all.
In my opinion it abides to the Wiccan Rede. It harms none. In the same manner I see it as a declaration of faith and loaylty. If I was Wiccan, and I truly felt that it was for me, I would tattoo both the God and Goddess symbols on my body. I heard this somewhere once, and it said "Your body is a blank canvas, paint it as you desire".
Far as peirceings go ive had a few. Nose, belly button, hand, tounge, eyebrow. To me its like an antenna especialy when you are new, learning and developing your senses. I dont have any now and never had any guages. My ears are still peirced. I have 5 holes that will never close, though its been years since i wore earings.
I personally have 10 piercings and I have 3 tattoos (including a pentacle on my wrist and a triple goddess over my heart) and my next tattoo is also going to be Wiccan related. I don't see it as destroying your "temple" but rather.. like a Christian Church and their stained glass windows, it's my way of beautifying my temple :)
Just found this thread and to tell you the utter truth there is nothing wrong with tattoos and piercings within the Wiccan religion. Im not wicca but know a few that got both . i got a few myself and as a famous writer once said" my body is my journal and my tattoos and piercings are my stories."