When Thomas Paine refers to material injuries in Common Sense, he is referring to how the British have restricted the colonists from developing their own economy. He indicated that Great Britain set up the colonies, not for the benefit of the colonists, but for the benefit of the British. He believed that Great Britain was restricting the colonists economically.
There were many restrictions that were placed on the colonists. They had to buy their products from Great Britain. They had to ship products that were made in the colonies on British ships. The same was true for products that they bought from Great Britain. They had to send raw materials to Great Britain so the British factories could make products for them. The British tried to give a monopoly on the tea trade to the British East India Company. Thomas Paine argued that the British didn’t have the best interests of the colonists in mind by having all of these restrictions. He believed that products made or grown in the colonies would compete in the world marketplace and would bring a fair price to the colonists if they could sell them wherever they wanted to sell them. This was one of many reasons why he felt the colonists should become independent from British rule.
What Paine is saying here is that the colonies suffer in a number of ways from being tied to Great Britain. The most important of these is economic.
Paine argues that the colonies do not need Britain economically. He says that their "corn" would be able to get "its price" in any country of Europe. He says that any country would be willing to export to the colonies. For these reasons, they don't really need England. At the same time, colonial trade is harmed by being tied to England. This is because England is always at war with someone. That prevents the colonies from trading with that country or countries. If America were not tied to England, they could remain neutral and keep trading. By being tied to Europe, America's options are limited and America is placed in danger that it would not otherwise be in.
When Paine talks about material injuries, he is speaking about economics.
Was Paine right to say that "Europe and not England is the parent country of America"? Why should that concept be considered a factor for separation?