I wanted to attach a file with the projects to this post so everyone can check the "concern 2" but I can't see this functionallity in this portal.
Thanks for answering our questions.
We will continue our development on Tomcat 7 for now. JBoss 7 will probably be our production server.
I can live with full application restarts because the application is written well and it start pretty quick. I would go for JRebel otherwise. We have some applications written in Vaadin framework, this almost only has Java code so you can see the point that incremetal deployment doesn't help here.