Google Partner Setup is an app that helps you run applications in conjunction with Google products. For example, with this application's help, you can use the calendar from your device with a ToDo app that you've just installed.
As for the intrusive permissions, you are right. I don't understand why it needs all those permissions, if all it does is interface with other Google products. This software cannot be downloaded or deleted because it comes with certain hardware.
I am not sure, what the result of deleting this app (on rooted device) could be. I have just greenified this app on my android tablet, I'll report back if I face any issues.