Thing is, that external systems have the plugins available that I need to build a functional site. But if me, myself and I build a bridge between UNA and wp-plugins, I guess it's my own business...
It would then also be my own business to let the bridge-module be available for free on my own site.
Safe? Sure it is safe. Wordpress is not done by beginners. There is a reason why they are big. If it wasn't safe, it would not be as big as it is.
But this actually made me smile a little bit. I can see now why UNA is not bigger. It's not about skill. It's about priorities. Not my problem though.