tango wrote What is the add to role feature under miscelaneous in products used for?

This defines security roles a product is associated with. When you place an order on the product, your account will be added to these roles automatically.

tango wrote id like to limit certain products to a user role. is this the way to do it?

No, this is not supported.

1. Put these products under a category.

2. Display the category on a page.

3. Make the page visible to that role only.

Make it invisible so it won't display on other pages.

On that page, go to module setting page and select that category as default category.