Two questions about subfolders in URLs:
1. Can I have more than 1 subfolder in a URL without negatively impact SEO practices?
I think it is most user friendly to make a subfolder for the category as well the product.
For example, is it ok to use domain.com/categoryname/productname/page.html if it`s the most logical structure for users?
2. Some products will fit in more than one category. The pages will slightly differ from each other (f.e. slightly different pages and text but not that much). Will rel=canonical solve this problem of duplicate content?