Streamlining Multi-site

Hello all,
I have a multi-site environment that I’m working with where I’m using folders for sites. I am trying to use the root’s theme as a central theme and want to “pipe” data flow from root to other sites within the network. The end user only interacts with the root theme,

My questions is: Is there a plugin or some sort of solution for non-programmers-but-curious-and-willing individual to accomplish this?

Thanks for help!