Is there a way within Indigo Studio to import high fidelity/color mock-up elements to a library and give them interactions contained within itself and reuse them in other Indigo studio projects and/or other screens with a project?
Not yet, but it's the highest voted feature in our UserVoice site: http://indigostudio.uservoice.com/, so it's has a big chance of being added in the near future.
You can vote for it if you want!
A lot has been going on since you wrote. I'm glad to tell you that our current version supports reusable components - screenparts -. In this link you can find more information about screenparts.
Once again, thank you for helping us make Indigo better. If you have any questions or more feedback about the product, we'd love to get your thoughts.
Best regards,ClaudiaIndigo Studio Team