No, you most likely cannot run SteamOS, unless someone makes a port of it. There is no google play store, but you can use the chrome web store, but there are not many good games there. I would not suggest getting a chromebox for gaming.
yes, they are safe, legal and are worth about 70$ a bitcoin. the only way to get them is called mining bitcoins and essentually that uses your graphics card to solve equations and find blocks. it takes a wile on a really good graphics card to uncover a block. the best way to get bitcoins is to...