Is there any way to implements the execution of the action (synch/asynch) in a sequence manner like 1.actionx on document/content , 2. actiony on document/content like that.
To perform multiple actions on the same document you can just define that using rules. But if you want multiple actions on multiple documents then you'll probably want to implement custom action in Java. For custom actions take a look at this: http://wiki.alfresco.com/wiki/Custom_Actions
Hope that helps. If not, then you must be more specific on what you are trying to achieve.