I am currently in the same situation with a similar component. I am including (with the data-sly-resource syntax) 2 different components.
One is a responsive image component that uses droptargets, the other is using a rich text editor component.
When I drag an asset on the responsive image, it will create the node required to save the data without any issue.
When I try to use the inplace editing of the text component, the dialog for this component fails. This is indeed due to the required node not existing.
This issue seems, as far as I have tested, to be limited to using the inplace editing feature.
The template way partially works but will only work if the component is set using a template to create a page. Any available component in the sidekick will continue to have this issue when it is dragged by an author.
I have currently patched this issue by creating a subnode in java when the component initializes and does not have the node for the nested text component. However I am still looking for a cleaner way to resolve this issue.