Re: schema.org weekend reading: Actions/Activities, Audience draft, and Class

Thank you for the new draft. IMO it has huge potential for hypermedia apis, since it is still an open question how a client could automatically pursue a goal like 'buy a cup of coffee' using apis of independent vendors. This draft could be the answer. 
In your example, the goal would be 'rent skyfall for online viewing', 'buy skyfall ticket for today'. 
You seem to envision that there must be lots of product specific actions, such as RentMovieOnline, RentCdOnline, RentMagazineOnline etc. There are however so many business models, that creating Thing specific Actions like these is an endless task (OrderBagelHomeDelivered... ). Wouldn't it be preferable to break up the Actions into sentences and define only the subject, predicate and object of the action, furthermore leveraging the offer-accept semantics you have already introduced? Rather than a BuyAction, there would only be the AcceptAction. 

Example:
Thing: Movie Skyfall
Offer: Ticket, Rental, Subscription, Transfer ownership 
Delivery: Home, Retrieve at location, Online
Medium: Physical, Stream, Binary copy, Printout

Thing: Bagel
Offer: Transfer ownership ;) 
Delivery: Home
Medium: Physical

This would give us a chance to have a quite complete description of possible actions clients could look for, at some point. 

Clients would always do the same thing: accept an offer by Posting an order. 

What do you think? 
Best regards
Dietrich