I've seen this asked for over the past year or so, but wanted to voice my desire for both new features.
Our workflow (as with others I'm sure) has been to maintain an exemplar website internally, where we create and improve upon different layouts and partials. These are starting points for new client work. A wireframe library, if you will.
Having the ability to turn these partials or entire pages into Webflow symbols is a great start, and I dig that feature already -- it's very helpful. But, being able to copy these symbols from one site/project to another is really important to maintain an effective workflow.
I've read all of the arguments regarding overwriting classes on the destination site, etc. -- and I don't think there is an easy technical solution for that, and personally don't care about that. All my starter symbols would be used to "setup" a new client site, saving a ton of time.
So, being able to copy symbols over will not only give us the layout and structure, but the benefit of having all my classes ready to go, too.
Related, being able to have a mechanism to define Class Variables (ala' Sass, Less, etc.) and refer to those variables in the Class editor would be very helpful for a typical workflow, too. That way, when I (fingers-crossed) copy over my "style guide" symbol to a new site, I can reconfigure the site's class variables, and now I have a head-start in rebranding. Another advantage would be, obviously, when a client decides they no longer like that shade of red on the site and want to replace it with another -- it can be taken care of in one place.
Thanks for a great product, @webflow.