It may be naive question. Is it possible to use Dynamo on Revit projects now ? I remember it to be restricted to mass environment only and Vasari, does something bypassed me? If is it possible, are there any limitations in using it ? I don’t know if dynamo became complementary to Revit API . Does it has the same functionality as Revit API?
Yes, you can use Dynamo in the project environment, too. Note that you will not be able to use certain nodes in a project (e.g. creating forms) or vice versa in a mass family (e.g. creating walls) - basically the same limitations apply that exist in the Revit UI.
Regarding the API: All available Revit-related nodes make use of the Revit API. However, not all functionalities the API provides are available in Dynamo (yet). If something you need is missing, you can access the Revit API with a Python node in order to make a custom node and publish it on the package manager. If you’re interested in that sort of thing you should have a look at the Python section of this forum (http://dynamobim.org/forums/topic-tag/python/). You can also code your own nodes in C#, but now is probably not a good time with the migration from 0.6.3 to 0.7.0 underway.