multiple networks, prosites and marketpress with amazon FPS

My multisite network will facilitate non-profit entities with free and pro level websites, and a social network for its network of field reps.
Question 1. Can I manage multiple multisite networks from a single super admin?
Question 2. Can the non-profits each be a multisite admin of their own network?
I think the following might work for this: http://wordpress.org/extend/plugins/networks-for-wordpress/

Visitors to pro level field rep websites should be able to make donations. Donations would be to the field rep for their project through the non-profit entity.
Pro-site upgrades would be based on one of several scenarios:
. The field rep pays for the upgrade
. The non-profit entity foots the bill for an entire network of field reps, cutting the cost per site
. Funds from Donations on a field rep site cover the cost of the upgrade. This would require the ability to split the payments to the super admin (for the cost of the pro-site upgrade) and the multisite admin (non-profit entity) who handles distributing donations and funding to the field reps
Amazon’s Flexible Payments Service (FPS) can facilitate transactions between a buyer and a third party seller, take a cut of the transaction, and have control over who pays the transaction processing fees
Question 3. Could I use a combination of Market Press and Prosites to accomplish this?
Question 4. Does Market Press work with Amazon’s FPS?

I’d like to offer an authenticated xml-rpc for the multisite admins
Question 5. How do I setup and use xml-rpc in this way?
Question 6. What api calls are available?
Question 7. What steps can I take to make custom api calls?