Yea, the specification of status codes is cumbersome and annoying to deal with, like you're supposed to go find a list of what they are supposed to be on wikipedia and then match it up to what's going in your application as best you can. Also the PUT, POST etc stuff. It's just a pain to try to match up your application's behavior to a crusty old spec that was never that good.
It's really refreshing to code with websockets and just write an application naturally. HTTP is good for GETing static web pages and that's about it.
Updating multiple resources of the same type is easy: POST to the plural form of the resource.
If you need to update multiple resources of different types atomically, then you probably need a new resource abstraction that covers both of the resources anyway. Then just POST to that.
It's really refreshing to code with websockets and just write an application naturally. HTTP is good for GETing static web pages and that's about it.