Can I dynamically create levels during gameplay? If not, is there anything I can do to achieve a similar effect so that I may create relatively small scenes that are essentially disconnected from the relatively large scene in which the small scenes are created, all of this during gameplay?
pretty much anything can be done at runtime. however your explanation lacks detail and is a bit difficult to understand what your looking to do. i can think of a few possible things you may be attempting say so clarification is needed,
Yes, spawning and destroying actors is no different from doing that in level editor, but creating large amount of actor in same time might cause visible freeze. By sound of example you said, you might also look in to level streaming:
Thanks for taking your time to read my question.
What I meant was that if I can create and delete maps the same way I spawn and destroy actors at runtime. Hope this clarifies the question:)
Thank you. 
That has been very helpful!