Is there ever a need to run init on the Model object before you inject your dependencies?
yes, there could be. Maybe you need to setup your object with dependencies in its constructor first. There are no wrong or right ways, you could go either with a constructor dependency or setter/injected dependency. It all depends on what you prefer. Maybe you want things to occur on initialization rather than after all setters have been injected. Therefore, constructor dependencies should be done, when the object’s constructor needs to use these dependencies in it’s initialization. I would say that most of the time, you will only be doing setter/injected dependencies. However, for constructor dependencies use the constructor arguments with the autowire markers.
luis