On 2) what is also interesting is to consider how suitable AS is as a generic set of social primitives, when the semantics of the activities aren't crystal clear.
For some activities things are easy, e.g. ones relating to CRUD-over-the-wire. But e.g. an as:Offer much less so.
I've seen Offer been discussed in very different (bounded) contexts, where semantics/meaning would be fundamentally different. These would have different (custom) props to distinguish them.