Hey guys!
That's true, there is some gap-bridging that definitely needs to take place between PayPal and Shopify, but at this current time the express gateway's workflow forces folks off site before they can make a payment. As Lorraine pointed out, if you use a separate credit card gateway, it does become a bit easier as customers can check out with a credit card right from checkout.shopify.com, or opt to go over to PayPal after information has been provided to the checkout server.
We generally encourage more than just the PayPal gateway, too. For example, merchants in North America can use Shopify Payments, which we encourage for folks whose businesses are compatible with our Terms of Service
http://shopify.com/admin/shopify-payments/terms
By signing up with SP, you're also able to have your transaction fees waived for your relevant plan level.
As for Shipping, we do have some developments coming, and while I can't say what they are or when they'll arrive, I can definitely say that this is something we're currently working on improving, and I can't wait until I can share it with you guys.
Matthew Buttler
Guru
Shopify Inc.