It is already possible to get all actions for custom app actions and objects:
https://graph.facebook.com/me/{appNameSpace}:{action}/{object}
This will list a
AFAIK there is no way to get all actions published by application via OpenGraph, but your application creates those actions, why just not record results of this operation?
Then you create action you should get response like this:
{
id: “{action-instance-id}”
}
Later you may read this action:
GET https://graph.facebook.com/{action-instance-id}
You for sure may benefit from doing request to get multiple actions like this:
GET https://graph.facebook.com/?ids={action-id1},{action-id2},{action-idn}
And even batch those requests