Sort of. Verbs are still eschewed so rather than finding a 'book' link, it would be a 'booking' link to which a POST could be made to create a new booking. As a note, "Booking" is a confusing example because while a hotel booking is a noun it at first glance reads as a progressive tense verb.
So instead of a hard coded url it's a hard coded reference to a url? How does it deal with a breaking changing? Say the order of the links changes? It doesn't seem like this works without some out of band information.
They are keyed using rels. You're right, they aren't relying on order; that would be terrible. And yes, JSON doesn't "have" rels. This is worked around by specifying a mimetype which does. Is it turtles all the way down? Yes, but not all turtles are equivalent. You should already be specifying a "Content-Type": application/json, it's not too much to change that to application/vnd.api+json and write a spec somewhere.
