In settings > General I have it set that anyone can register. And that New User Default Role is set to “Customer”
Why are customers assigned an affiliate number, and why are they able to view the stats ext when they are only a customer? How can I make that so only affiliates are able to view this and are the only ones issued an affiliate link?
Edited, code moved to pastebin: http://pastebin.com/0PcbWy6D
“Why are customers assigned an affiliate number”
This would only happen if you automatically create affiliate accounts for new users such as when using the Affiliates Users extension.
“, and why are they able to view the stats ext when they are only a customer?”
Only affiliates are able to see their own stats. If you refer to viewing stats on the administrative back end, make sure that you have not enabled the Customer role for permissions that should only be granted to administrative roles.