Question from a BUYER regarding customer info.

It seems 95% of my Amazon purchases are from 3rd party sellers (99% are shipped by AMZ) as long as I have been with them (23+ years) and I have never had a problem but I have a question:

When something is purchased from you & shipped by Amazon what PERSONAL info does the SELLER get regarding the buyer? Since Amazon ships it do you get Name? Address? Phone? Nothing?

What about on returns that go back to Amazon? What info do you get if I return something? Are the returns sent back to you as they come in or in bulk?

Thanks, always wondered how that works.