Can I let others (not my students) also view my Teaching Plan assignments, for a teaching portfolio?

You can simply share the read-only link of the project in those cases, if you wish—that will allow the other students to see the project, and clone it if they wish to use it.

If you're happy to make them public, you could also consider publishing them in our Gallery. This would make them easily accessible / discoverable by students not in your class, and allow you to add some additional context, by way of a short description and license for use. If this sounds like it might be of interest, you can find out more details in this short guide.