I think it's going to hurt a whole hell of a lot, both physically and financially. With multiple sessions to make the outline, and color it in. Also know that with age, the skin wrinkles, and so do those tattoos. So what looks pretty when you were young will look like crap when you get older.
If it's not your personality, then yes it's too much. If your a biker, tomboy, mechanic, car person, then sure it fits you. But that is more of the punk, with piercings and the like. Many times people get tattoos because they have meaning, like beating cancer, or a child being born. What is your reasoning to get a full back tattoo? It's not my fancy, but it's not horrible.
It could be too much depending on your personality. But I would say don't get it unless it has significance, because it's going to look like crap in your later years.
Not if you are in a biker gang or something. Smaller would be okay in my taste. Maybe half size, BUT 'tis only my opinion. If its your first, I would suggest something smaller and cheaper because you WILL want more. They're addictive.