Let me first start off with stating that I'm an EVE player and an avid defender of EVE's sandbox/player driven content and interaction, so I'm obviously biased. But then, who isn't.
To me an MMO is about interaction with other players, if there's no meaningful interaction then you might as well player single player (See Skyrim vs. ESO, ESO is a half ***** attempt where the player interaction is messed up and as such it's terrible at being an MMO, making Skyrim the better game). Meaningful interaction can happen in various ways but regardless of it being positive/building or negative/destroying, it's all interaction and it all adds to the immersive universe.
While ED is never going to be on the same level of player interaction as EVE, it should have it... and lots of it because if there's no player created content (in whatever form) then you're stuck with grind content because that's really the only other option. That's why normal MMO's need a content patch giving you more levels, gear and whatnot. It's a GRIND and personally I'm actually rather offended by it because it means that the devs simply assume I'm easily entertained and am incapable of seeing through the terribleness.
In order to have meaningful player interaction the game needs to allow for people to excel and to fail, this creates goals (defined by the player himself) and hurdles (defined by the other players) and thus perpetually creates content. If there's none (or not enough) then all you're left with is mining or doing trade runs like an autistic grind bot.
So, as I see it, there should be as little rules, regulations and limitations as possible (apart from the EULA etc) because it allows for content, meaningful player interaction, contest and continued reasons to keep playing.
On top of all that; we're in SPACE, it's uncontrolled anarchy, and if you want to survive and do well you better be prepared to battle (in whatever way) other people trying to do the same. We're not all individual snowflakes destined for greatness, it's an emergent potpourri of players all trying to survive. That's what I'm looking for in a space game.