Strange Propane Tubing in European Travel Trailer

Forget the pictures !
If you don't like it, replace it w/ hose and barbed fittings.
There is nothing special about propane hose, infact in some cases it has been known to be of very poor quality.
Anything after the regulator, I use automotive fuel injection hose. There is no higher quality. For the long runs to my Cat heaters, I use the clear vinyl hose found at any hardware store. Don't be fooled by that expensive low quality "propane hose"