Is it possilbe to create navigation referencing pages from config? (but not as external urls)
Sometimes its hard to reorder navigation items when you have to open ie 10 files (and find them first).
Yes, as demonstrated in the example in the docs:
That way you cannot acces .Page of menu item nor use .IsMenuCurrent
It sounds like you have a different question.
totally same but if you add page to navigation using config, you get limited access to that object (only url and name). If you add page using pages’ params you can access that .Page object with all params and methods