This is a Shimano Tiagra ST-4500 shifter. More explicitly the problem is with the Tiagra Double controlling the front derailleur.
1) The barrel adjuster is hard to use because all parts around it seem to move when I turn it. Only when I firmly hold one part of the adjuster and turn the other, it does what it's supposed to do. 2) When relaxing the cabling I can simply pull the outer casings out everywhere like shown in the picture.
Compared to the rear shifter which currently looks more solid (and where the adjuster is usable as one is used to it) this feels like a mess. How are these components usually kept together? Does something need glue? Or lube?