Fundraising and its payment gateways for advanced crowdfunding

I would like to understand two points related to Fundraising plugin payment for :
1) can it work with payment gateways other than Paypal (for instance Braintree) and what kind of development need to be done for this?
2) For PayPal, can it work with REST API (and thus use the API credentials that are available "off the shelf") or it's a requirement to use SOAP API and undergo the horrible Paypal approval process?