If I buy your theme, can I use elements from Enfold Classic and Elegant Portfolio in one site?
Basically, can I integrate features of Elegant Portfolio into Classic or Parallax, etc. for a single website?
All elements in the demos are available in the Layout Builder in Enfold, so the short answer to your question is yes. If you need to copy content from one demo to another, then you can do that by activating debug mode: https://kriesi.at/documentation/enfold/intro-to-advanced-layout-builder/#debug-mode