ii) Much of your essay details the damage done by these alternative sources, but you still say it's very important that we find them.
Also, are you sure about the historical accuracy of your first sentence?
On a brighter note, thank you for taking note of my advice about ellipsis ; however, try not to use them too often. When you use 'for example', you don't need to follow the list with an ellipsis: you have already indicated that your list is not complete. So, I'd delete the second one.