We Need States

What you consider legal confusion is a feature of the system rather than a bug. No, it is not morally different to murder a person in California than in Illinois, but the matter of what is the appropriate punishment is a matter rational people can disagree on. I would in fact suggest that nobody knows the right answer. Allowing California and Illinois to experiment separately with what that answer ought to be seems like a reasonable solution to me.I'd view gun laws in the same way. Within the confines of the 2nd amendment, I don't see why states cannot experiment with what works for them. I don't think this is quite the problem it used to be. It is completely feasible using modern methods to produce whatever textbooks states want. For example, Virginia manages to produce its own, riddled with errors, history text books and has no interest in the text books that Texas uses. Not quite. State laws apply to you if you operate a corporation within that state. Primarily what you get by incorporating in Delaware is a standardized set of formalities and some law applying to shareholder's rights with respect to corporations. States can and do decide the overwhelming majority of the substantive law that applies to corporations.I don't disagree with all of your points, but the "legal confusion" or non-homogeneous state law argument one isn't a one sided slam dunk in favor of getting rid of states.I don't see why some hick in North Carolina should have any say in whether some drug is legal for recreation use in Oregon. Why is the current situation less democratic than having the entire country vote on the issue, when it doesn't affect the overwhelming majority of us?

I don't see your states "do stuff" as an insurmountable obstacle. Under the constitution, there are many things that the feds do not do because they are not empowered to do them. The constitution leaves policing powers to local authorities. So states manage education, local crime fighting, intrastate commerce, etc.Historically we had states before we had a union. If that were not the case, there is no reason why policing powers could not flow from the federal government to regional managers under federal oversight.In short it is not persuasive to simply look at what states do now and to insist that those functions would not be carried out without states. We know that local and federal governments would pick up the slack. What is of interest are the ramifications of having the federal government involved in so much.State governments are no guarantee against tyrrany. Historically we've seen lots of cases where federal law was the only insurer of personal freedom against the states.

That's correct, but a state is to adopt what works in other states if that solution fits. And the citizens can make that decision with a lot more practical information. And American citizens are free to move about to situations of their liking.