Post Categories and Portfolio Categories

Before purchasing Enfold, I was using another theme and made individual posts to display my videos. Each post included 1 or more related videos and a bit of copy about that type of video. Each post was a “case study” of sorts that served as a portfolio – to demonstrate a type of video my customer might consider using and why. As a result, I had over 20 sub categories under the (parent) video category. For example, I had subcategories like event video, how-to video, news video, location tour, etc.

When I applied the Enfold theme, I started experimenting with various layouts and have cobbled together a bit of the options…but the portfolio section is not working the way I would like. If I had been building a website from the beginning, I assume that instead of post categories I would have made portfolio categories for each of these subcategories and displaying them would be simple.

Unfortunately, the categories referenced in the portfolio items seem to be totally separate from post categories. Can I connect a category called Video in Post Categories with the Video category in Portfolio Categories?

Short of starting over, is there a way to utilize the portfolio items with the post categories and/or tags that I have already assigned to my existing posts? I thought about adding portfolio categories with the same names, but assume that would cause trouble. In this situation, is it possible to switch between other themes and Enfold without having to re-enter all of the information previously in posts? Unfortunately, all of those posts (and their assigned URLs) are already out there and indexed so if I have to re-enter them I will have duplicate content all over the website.

Any suggestions please?
I’m finding this hard to sort out because I don’t really understand the way portfolio items are different from custom pages or how post categories and portfolio categories might work together. I’ve watched the videos and read the documentation, but most of it assumes that you are starting a new website.

Thank you for any documentation or information you can provide.