Elite 4 is going to be open, like Elite and Frontier- This means that you will be free to do whatever you want, and fly to wherever you feel like. Of course you have earn money first so you can pay for the fuel, servicing, weapons, etc. To give you a better idea of what an open game is, take a look at Privateer and Wing Commander. In Wing Commander you have to follow a certain sequence of missions, and you cannot choose what you want to do. Just follow the orders, and do your missions, otherwise the game ends. In Privateer you are free to either join the plot, trade, do random missions, etc.