this url will help you with your photox queries
http://www.photoboxgallery.com/content/gallery-faq#earn
Photobox is free to register
i upload my pics through my bootsphoto account and add them to my photobox porfolio after that you create links via your website pics direct to photobox gallery
as regards paypal account direct debit system
what happens paypal deposit to small amounts into your account this to verify your are who you say you are
this will allow you to tranfer money both ways paypal is no less safe than any other online banking.
your problems arise when you accept payment and send goods to unverified
paypal address
hope this helps