I’m heaving some questions again, looking for your help.
1) Is it possible to create multiple portfolio pages with different portfolio items (so that portfolio pages won’t show all of the existing portfolio projects)?
2) Can portfolio item link to a page but not to a project item?
1). In principle, it is possible to create a new content type that would be analogous to the existing “project”-type items, and a custom page template to display these new items, yet it is not envisaged by the theme and I would thus classify it as a customization work and have to charge a symbolic fee for that. In case you are interested, please send me an email to email@example.com.
2). Portfolio pages can be customized to display pages, yet all of them would appear on each portfolio page then. I am not sure why you need to link to a page instead of a project – what kind of functionality can a page offer that a project can’t?