There is nothing really JSF-specific about them. The only minor exception is that in Seam 2.0, the Home classes create a FacesMessage on each operation, but in Seam 2.1 this has been changed to a StatusMessage which is pluggable to any UI framework that provides an implementation (otherwise is it just ignored).
Keep in mind that the Seam Application Framework classes are useful when time is of the essense for you. If you are developing a system that is heavily invested, you may find that you quickly outgrow this framework. In that case, you can use it as a proof of concept. You should never feel forced to use something. That is the Seam way (i.e. your way).
Many thanks for the reply Dan.
I've read through the Seam reference documentation and the chapter in Seam in Action about the Seam Application Framework but I'm still a bit confused about what it actually provides and its limitations.
You mention that I might find that I quickly outgrow the framework - I'd be really grateful for some idea of what you see as being some of the potential limitations that I might hit, and what the alternatives might look like.
I had a similar question in Dan's Seam in Action forum.
At that point, I was going around in circles Seam/Spring or Seam
I decided to cut Spring out completely and started with a seam-gen JPA/POJO template.
I am still a newbie so I do admit that I still do not understand the limitations of the Seam Application Framework.
I do see a lot of posts in this forum with code references to EntityQuery & EntityHome though I wonder if there is anybody out there who has a production application built entirely on this framework.