One observation from using Nitch now for almost two years is that GTD is not only about projects and actions, but a higher level concept on top of projects is still needed. I added roles and goals earlier to Nitch, and while that has been helpful to bring projects and actions into focus as needed, I still ended up too opften with projects that did not have a clear outcome.
The concept of a goal looks promising in this context, and I am adding more functionality to Nitch to have goals which in turn are made of projects. That allows to use goals for more longer term planning, and restrict projects to efforts which are not longer than a month.