Hello there,
First of all, I read your project and I would like to congratulate you for your clarity. I read dozens of descriptions every day that are much more verbose and, at the same time, express much less about what is really needed.
Well, about your requirements, to use your node module as you want you actually need to access two BrightCloud resources, one for getting the categories for an url and other for getting details for all categories, or you will end up with a JSON containing only a list of categories ids.
I will charge you $155 for those two methods in your node module, and I need at least a couple of days to deliver the work.
I would like to invite you to call me on Skype to discuss your project, so we can understand better each other ideas. Please add my skypename: fqborges. We can also discuss further how much it will take to add more functionality to the module when you call me.
Thanks,
Filipe Borges