Let me take on this first:
OF COURSE Nethserver is for both home and business! But IMO when the developing resources are limited, attention for the base modules should be focussed on primary functions like network services and security.
Apart from that there can be a million very interesting and attractive addons, plugins and modules.
Maybe it would be a good idea to have some kind of 'universe repository' (yes I come from Ubuntu 
) for external modules that are maintained outside the scope of the main devs.
I know it is very hard to find people that have enough knowledge and time to develop and maintain a module, but ultimately that would be a great way to extend Nethserver.
Besides adding extra native modules, it should be possible to manually install any application that doesn't interfere with Nethserver templates. Do pointers on how to approach this exist in the docs? (still new and didn't read all the docs yet)