They quite literally built a system in place to add amendments to the constitution and to take them away if needed. Why would they have done so if the intention was to keep the law static until the end of time?
They also made it remarkably difficult to amend. They wouldn't have done that if they thought it should frequently change.
The economy fell apart, the states were constantly squabbling over petty things, we had Shay's rebellion, the nation's debts weren't being payed. The currency of the time had no value. Britain was screwing the country over with it's blockade (which couldn't be solved due to the lack of any federal power). The articles of confederation was such a disaster that it had such a short lived life that the founders themselves got rid of it.
I understand the frustrations, though those points are a biased history. I don't think the founders would have abandoned the Articles if they could have foreseen the behemoth they created in its place. But indeed they did, and honestly I'd be okay with it if we'd just stick to their original design.
Politicians have power by definition, and corporations have a direct incentive to get as much power as they can.
The singular goal of the American republic is to limit the power of politicians. That's basically what the Constitution's all about.
Corporations do not seek power. They seek sales. And they gain sales by offering goods and services that people want more than their own money. It's not having power over someone to sell them something they love.
So states should regulate commerce, but not the federal government, is that what you mean to say?
Affirmative.
If so, then how would that work out for situations where the regulation/unregualtion in surrounding states impacts a different state? For example, if california legalized weed and had the effect of making weed more available to the surrounding states, how would those surrounding states deal with it?
States make agreements with their neighbors, much like reciprocity for CCW licenses. Indeed the whole Union is meant to pretty much be a coalition, so if South America were to invade Texas, New Mexico, Arizona, and California, for instance, the rest of the states are supposed to send their militias south to help defend the border. If Oregon legalized marijuana and Idaho didn't (to use a real-life example of bordering states), then LEOs in Idaho can look a bit more suspiciously at people with Oregon plates, and possibly pull them over and see what they smell. A more extreme solution would be to erect border checkpoints to conduct "random" searches.
If everything was small business and there was greater power in the hands of laborers, and if the internet didn't exist then maybe this would be true. But the modern reality is not like that.
But reality is like that. Have a look here. I want to copy and paste the whole page.