I agree wholeheartedly with the OP about how this is basically a roleplaying game, whether each player intentionally approaches it that way or not. I do think there are a few extenuating circumstances, which complicate the idea that "you should follow the rules of the society in which you now find yourself."
The first small complication is that the game starts every single player with a gun in their hand. Some people will buy this game without doing much research first, so they won't know in advance the depth it has for doing things besides killing other ships. Taken on face value, the game does pretty much say "go out and kill something" from the very first frame.
I don't think that should change, given the focus of the earlier games in the series and the worldbuilding concept that you're entering a dangerous Galaxy. But I think we have to go a little easy on people who follow the lead the game gives them, right from the start. Maybe there will be more guidance in the final game, possibly a different focus in the tutorials? But this problem will still exist to a degree. Put anyone in a sandbox game or RPG with a gun in their hand, and it generates expectations for what the game is about.
There should be plenty of knuckle-slapping by the Authorities in the starter systems to reinforce the "social contract" in those systems, but in a way, it's fighting the initial impression the game gives you.
The other complication is that while I agree, in general, with the premise that we should follow the rules of the society in which we find ourselves, those rules will change across the gradient from civilized core systems to a relatively lawless and sparsely populated frontier. And then beyond, into deep space. Players will be able to choose where they want to operate along that gradient, including out on the fringe where there will be no rules aside from the ones you adopt for yourself.
It's going to be fascinating to see how that plays out, because the most antisocial form of PvP, the type even many PvP-focused players don't condone, almost requires being close to the core systems where new players are learning how the game works, and where it's a "target rich" environment compared to the outer fringes. Out on the true frontier, you're likely to meet only the more hardened ships and pilots. There might be an informal "Code of the West" adopted in those areas, where you don't lightly take on another pilot in combat without good reason, and some risk. Interesting times ahead, I think.
Nice post. Well thought out. +1