C++ Projects and the Marketplace

Hey guys i’m making a project template that is intended to be used as an starting point for certain projects:

I was wondering if i will have any issue if i make this as a C++/BP project (not as a plugin). I know that C++ projects are normally submitted as plugins but as my project is not intended to be merged to existing projects, can i submit this to the marketplace or epic will not allow it?

Also, is there a problem if i use 3rd party APIS/libraries such as facebook, gamesparks, etc?