TOPIC:

How do you create a rule that applies to a category and all sub categories? Do you have an example?

Dear Castus,
What exactly do you mean by "applies to a category and all subcategories"? In our plugin, the rules always apply to the whole cart. But you can evaluate all variables (amount, # of articles, weight, etc.) for a category (either including all subcategories or not), a vendor, a shipping class etc.
The details of the rules always depend on the details of your shipping cost structure, so a little more detail about your shipping costs would help a lot.

In general, let's say you want to apply free shipping if there are at least 5 articles from category "books" and its subcategories. You would use the evaluate_for_subcategories function to get the number of articles from the books category and its subcategories and use that in the comparison:
Best regards,
Reinhold