I'm not talking about a quest. I'm talking about lets say you decided to become a pirate and you attack another player, You disable their ship, board them take all of their cargo. Sell it but then you get a crime stat which means a bounty hunter can go after you and get payed for killing you. Then you get killed by a bounty hunter and get sent to prison. While you are in prison you can either work your way out, join a prison gang or break out of prison. If you break out of prison then you need to get to a security station, hack hte computer to clear your crime stat.
As for salvage currently you can strip the hulls of destroyed ships and either sell the material or use it to repair your own ship. They are currently adding ship componets so lets say your ship is damaged in a battle and your engines break or your sheild generator. Well if salavage an enemy ship you might find componets you can use to repair or replace the ones on your ship.
I'm not just talking about RP obvioulsy as Star citizen is also a sand box but there are actual game mechanics that allow that to be possible.
All of this in an open world with 0 loading screens once you load into the game. If you see something in the game you can get there. No invisible walls everything is physical in the universe.