|I also think that if you cant go to church or a formal situation with your hair color/cut without getting embarrased then you shouldnt have it that way.|
I'd allow whatever weird stuff they wanted to do to their hair. And if they did something exceedingly ridiculous, I'd make fun of them for it. Nothing stops a rebelious child like a parent laughing at the rebelion. Or saying "well, that's nice dear". Trust me. There's a reason I didn't do anything like that. Anytime I tried anything remotely rebelious, I got a "aww, that's cute".
I dated a guy with green hair in high school, and my mom said she liked the color. Kinda defeats the purpose. His mother laughed at him for the terrible home dye-job, helped him fix it, and then made him bleach the mess he made in the bathroom.
My cousin also went green. My grandmother shook her head, but he still went and held the altar candle. God loves all colors. After a week, she got used to it.
Piercings close up, but can be dangerous. I would discuss this thoroughly with my child. No piercings until 12, so they can be responsible enough to clean them properly. Piercings are supervised by the parents. Again, I was allowed to get piercings under these rules, and all I did was my ears lobes. My mom was actually upset that I didn't get a cartiledge piercing on my upper ear, she thought it would be cute. If I wanted a belly ring, she would have been fine with it as long as I could show that I would take care of it.
Tatoos are a different story, since they're permanent. No tatoos until 18. And if they wanted one, I'd advise them to a) not get someones name and b) don't put it someplace that will change shape.