ToDoList (not exhaustive)

Complete iptables roles and use it (maybe only for non-firewalld systems).
Create backup roles (server and clients) + git clone --mirror of the GIT repositories to backup them.
Create monitoring roles (server and clients) : Icinga and Munin.
Add a pre-task which can install python-apt, gentoolkit or python-yum if not installed (with shell module).
Add roles for different function (DNS resolvers, VPN server, BGP router, ...)