global cart

I have global cart enabled, but still people can checkout from all of the individual stores.

individual store: http://www.ybrmarket.com.au/thelittlehumbugs/store/shopping-cart/
global store: http://www.ybrmarket.com.au/store/shopping-cart/ (i hardcoded the checkout link in the side bar)

am i right by saying

"buy now" buttons don't work with global carts because the user is directed to the individual store?

and

"add to cart" is not the default button but it should be if the global cart option is selected?