I would change the cable adjuster, cable and housing.
"Why is their an adjuster there?" <--- some bikes have cable adjuster there, other ones doesnt, there is no rule about where u put them, in a matter of fact you can ran the bike w/o able adjusters because the RD has a cable adjuster already (at least campagnolo ones) and the FD pretty much doesnt need one at all. The other detail... like 95% of the cycling population has no idea what are those things for"