Coming from a seventeen year old East coast US girl...
In my opinion, piercings aren't bad at all. They can be taken out if necessary, and seem to be a way of expressing yourself in a way that isn't offensive to anyone else. I like piercings, they are unique and depending on the type, can make a person more classy and elegant. Tattoos also, if well thought out and placed, are okay. I, personally don't mind them anywhere, but some people seem to have a problem with them. As long as a person has reason behind it, I think that others should support them with their motives.
When I see a person in all black, I see a person who has chosen this style for a reason that is important to them. I, myself, do not do it, but that is just because I LOVE colors.
However, if they like their style, then I say go for it! People should be allowed to express themselves however they want and not be judged for it. I mean, afterall, America is a free country, and we talk about how judging others by how they look is wrong...
And lastly, crazy hair... I love it! Its a lot of fun and a stage that most people go through during at least one part of their life. It is a way of freely expressing yourself, and in my opinion, can be almost like a piece of art that you can take with you! If done properly, I think it can look pretty good actually. Also, it is just hair... If you don't like it, or change your mind about the crazy style or color, you can just wait for your hair to grow out or re-dye it.
All in all, in my opinion, what you do to yourself isn't affecting anyone else around you other than if they find it aesthetically unappealing, and it shouldn't matter what anyone else thinks but you. If you are happy, then do what you want. People will get over it and either learn to accept it, or move on.
Hope that was good. :]