The cards are just representations of texts (or folders), it’s a different way to look at them (the outliner is another).
The idea is that you have a number of texts, maybe folders, let’s say every text is a chapter of a book. In the binder on the left you can see the structure of the text and you can easily re-structure the order of these text chunks.
But if the short names of the chapters you see in the binder are not enough for you then you might switch to cork board view. Here you not only see the chapters in their present order, you can also add synopses which will help you to tell which is which.
And if that still is not enough you might switch to outliner view where you can add even more info like the status of the text (is it just a draft, a final version &c.) or a label of your choice.
It depends on your needs and on the way your brain is ticking which method to get an overview you prefer. You might find your personal favorite you stick to all the time, you might switch a lot â€“ Scrivener offers more than one way, you chose.
But again, this is to get an overview over your project. Neither the cork board cards nor the outliner were made to contain huge amount of text (a synopsis is not a synopsis if it has the length of a novel).
Open the inspector and there you will find the notes section with both document and project notes. Unload here.
And don’t worry about having to buy another licence:
Rumour has it that the first word ever Keith spoke was “generous”.