Global cart + MarketPress Chained Payments

WP. 3.1.2 multisite
MP beta 2.0 4 (I saw the thread that 2.0 was launched but my updates doesn't show the upgrade option yet)
Question- A little bit confused about chained and parallel payments. I have a a main site with sub stores. Sub stores pay a % of sales to the main site.
1) If I want buyers to place items in to their global shopping cart and PayPal to disburse small fee to main site and then pay all sub sites (up to 10 items), I am using Chained Payments, correct?
2) Therefore in Network> MarketPress I enter information for BOTH PayPal Chained Payments AND PayPal Express Global Cart Setting? So I am pretty much entering the same information (PayPal APi, PayPal password etc) twice?