We all know documentations can be poorly writting sometimes, but Paypal's documentation really is on another level. I've been trying to wrap my head around the Express Checkout server side rest API, to no avail.
A couple of questions:
Yes, of course it's possible. PayPal's documentation is great, but it's just a matter of knowing exactly what you need. They have so many products and options for integrating their services that it can be a bit overwhelming.
Here is a quick reference for all the REST APIs. For recurring payments you'll want to study the Billing Agreements and Billing Plans sections.
Another option which would make things very quick and easy is to take a look at our PayPal PHP class library. It has functional samples and empty templates for all the Express Checkout calls.