This may be off topic, but since you felt the need to write an essay on the topic of the moralities of law, I hope you don't mind me offering my 2 cents. I am by no means a professional writer nor philosopher, and you may well regard me as an ignorant internet bloke, but this is my viewpoint as both a reader/gamer:
Don't you feel that you're looking at it in a very black and white perspective? I agree with sunandshadow in the fact that its an idea that is hard to comprehend on a common sense level of a general wide audience. It is because of this that he (or she) mentioned that it's a philosophy that you would have to slap the reader over the head with for them to understand. This is simply because your idea isn't very well relatable.
The purpose of law isn't to protect the well-being of those under it, it is to protect the interests of those writing it, even if that is to the detriment of those living under it.
This your thesis. The below is how you supported it. You also might want to note that you are specifically talking about the US Laws.
While most laws are benign, once examined benign laws serve no purpose. Practically nobody would do any of the outlawed actions in benign laws if they were legal, and those who would aren't going to follow the law anyway.
And this is your support. You use the ban on heroin as your example and claim that no one in their right mind would use it in the first place. Note however in the old days when heroin was not outlawed, many people at first did not know of its very harmful effects. They only hear about the ecstasy it brought, and then once taken they get horribly addicted to it. Think about teenagers who live in the now rather then the future who don't think twice about taking a risk. I know it seems obvious in this time and age, but back then, it wasn't. Same with moon shine and other toxic drinks and drugs. It served a purpose to inform and protect the public from those trying to trick folks who didn't know better. And look where we are now. Now its common knowledge thanks to it.
Since the presence of a black market is also a safety hazard, this law does a great deal of harm and no good. And that's how law always functions. If it's actually a bad idea, most people won't do it legal or not.
Again, you use strong words that paint a very black and white picture of laws. "Does a great deal of harm and no good" along with "that's how laws always functions." Do laws simply fall under good and bad?
You fail to neglect things such as "murder" or "child abuse." Does outlawing either of these things really harm people? Does it not do good? Think back in the medieval era where people murdered family members to acquire their wealth. To them, this was common sense. Why wouldn't you benefit yourself by murdering that brother of yours that you've always hated so you can get your father's land all to yourself?
The laws of the US aren't perfect. And you are correct in assuming that some laws are very much for the benefit of big corporation and government officials. But take note you shouldn't generalize laws.
I mean, look at the 10 Commandments of the bible. Those are moral laws dictated by the bible for people to follow. Is that also bad?
A kindergarden teacher puts down rules for kids in class. These are moral laws meant to keep order. Is the teacher taking away the rights of students immoral?
Laws are inherently in place as such to keep order. (Hence, the "common sense" laws sometimes isn't shared among individuals.)
Your argument revolves around the politics of the creation of specific laws by the US government. As such, it feels hard to relate to simply because you are generalizing "all laws are bad" rather then "laws made through politicians and government officials are often detrimental."
My suggestion, if you really wish to weave this idea into a story, is to narrow down your generalization. Make people take a look at the specifics rather then a broad (and lofty) agenda of declaring laws as plain bad. And (as said before) weave a tale to entertain first before subtly hiding your message away in the folds. You want to entice your player base first with something they might enjoy before tricking them into engaging in philosophical thought. You have the write to share your opinion with others, but you shouldn't expect people to always be able to understand or sympathize with your cause.
No matter how well you present it, there will never be a guarantee that readers (or players) will even bother to read into the details of your moral message. And unless you want to write a pamphlet on your philosophical view point, you shouldn't be bothered by it when most (if not all) your viewers pass your opinion over without a glance and get lost in the entertaining interactive aspect of your game.