Praxeology, by definition, is the the study of purposeful human action - which includes studying the means chosen to attain ends - and so it encompasses economics. To fully release the power of praxeology it is important that the underlying human ontological model is developed to its fullest.
Humans are physical and intellectual and this is the ontological model underlying the current approach to praxeology. That is an insufficient and therefore incomplete model. Humans are physical, intellectual, and spiritual.
How does this change praxeology? Subtly and profoundly! In simplest terms the definition of praxeology becomes the study of purposeful action by spiritual beings. This expands all of the praxeological sciences beyond the narrower constraints imposed by the less realistic ontological model.