I am a self-declared newbie when it comes to working with Power Apps. I've been experimenting with the platform over the past few months and have built my first two apps and several flows that work alongside them.
When I first started with Power Apps I was using Excel as a data source, but quickly realized that was not the optimal choice so I switched over to SharePoint. Now I see I have an Excel (Online Business) connection in my solution. I am thinking that may be from my original attempt at creating and app (using Excel as a data source) and thus no longer used, but how can I be sure? What are the implications if I choose to delete that connection from my solution (in the interest of keeping the solution clutter free)? Excel (Online Business) is not listed in either app under the Data section however it is used in my flows.
Similar question with the SharePoint connections. How can I tell what is using them? Why are there two? Do they need to be in the solution? What happens if I delete them from the solution?

...And a related question about the actual connections found on the Connections Tab in Power Apps. Why is SharePoint listed 4 times? Can any be deleted and if so what might be the implications? Breaking one of my apps that I have spent countless hours building is one of my largest fears...
Same goes for the Excel connector being listed 3 times (2 of which appear to be having an issue logging in).
