PayPal Adaptive Payments info

PayPal Adaptive Payments info

I'm writing to inquire about the various features Paypal Adaptive Payments
offer. I'm currently working with a team to create a travel site that
enables users to crowdfund for various trips (think Kickstarter for
travelers).
To provide you an example of a user on our site: Soccer team 'X' from
Africa is looking to crowdfund its trip to Europe to attend a soccer
tournament. Joseph, the team manager, creates a fundraising campaign on
our site with a fundraising goal of $1,000 and a 1 month deadline.
Questions:
Does the PayPal Adaptive Payments API allow us to keep funding on Joseph's
file until a trip is fully funded?
If the trip isn't funded or goal wasn't reached before deadline, is there
a way in which all the money can be refunded back to all the donors?
Unlike Amazon Web Payments, is the Paypal Adaptive Payments platform
available for international users as well?
Any insight would be greatly appreciated!
Thanks,
Farhad