None at all. Most graffiti artists are gangsters and drop-outs of high-school
That depends on the Artist, what it's on, and how much coverage.
The real name of the Graffiti artist that calls himself Phase two is Lonny Wood. The Graffiti artist is from The Bronx and is a much acclaimed artist from the 70's.
Some people don't really do much some people paint over it or leave because there are really great graffiti artist.
The answer to this varies based on the demand for the particular Artist's work. Most Artist's, regardless of the medium start their pricing low when they first start out, although thought must be given to the cost of supplies etc.
Highly variable - depending on who you work for. Ranges from high-school all the way to post-grad.
A graffiti artist named Zion. But there's too much Zions in the US and Europe to know who's the right one that painted those graffitis in the music video...
$10000000
generally the artist wants their work to be recognized, so they usually tag a much more publicly seen wall.
26,000
Depends on the school you will receive your education from and the specific training you need
high school graduate...year round training
Have artistic talent. That's really it. If you have original ideas and a good style then your good. Avoid being toy or else people will DEFF hate on you and buff you out. Just try to get up as much as you can, if this is what your going for it's not a matter of if you get busted by cops, it's when. Meet other graff writers and get a crew together. Most of all, just have your own style.