Contributor

Nope, registered means he qualify and can use this site.

You have to have given away $x of games in order to enter contributor giveaways with $x value.

to enter those your cv(value of games gifted basically) has to equal or exceed that number

generally the cv is the value steam store has it listed for(so a $5 game is 5 cv)
some exceptions, like bundle games(with an ) are capped at $30($25 true value, the rest is 20% of that 25) or 20% of non or something along those lines, but