When other marketers ask for my PayPal email address so they can pay me,
should I give them the one I use to login to my account with on the PayPal website,
or the one that is visible on My website when customers buy something?
You can use any email address so long as it is associated with your paypal account.
You can assign up to 6 email addresses to your paypal account.
Correction, you can have up to 8 verified email addresses associated with your PayPal Account. See this link.