PayPal stores user addresses for quick shipping entry. The question I have is, should I have the PayPal vs. native pay option right at the front of the process, so all information is handled by PayPal if the user so chooses, or collect shipping info at front one way or the other and leave the PP/native option strictly for payment?
Assuming you want to do right to your customer (and store) by making the payment and shipping flow as short and hassle-less as possible, I'd offer them the option to choice as soon as possible
A. 'Quick pay purchase' with PayPal (Or 'x-click purchase', or..) B. Manual check-out (or whomever you like to call the 'native' option)
If they choose A, you can show the pre-filled shipping & invoicing address, and offer the user the chance to change it, or confirm and proceed. (I'd take payment only AFTER shipping and/or info addresses are confirmed, as you might need to determine shipping, costs?)
If they choose B, after shipping & payment, you can offer to create an account on your website and store the shipping address for future use.
You should have a look at the Amazon process, although they do not use paypal, their 'choose another shipping address' & different shipping addresses according to your credit cards, is exemplary well done.