Sorry I assumed you were using an Ultegra chain also.
Your derailleur looks a littttttle stretched out to me. The chain should never be almost straight at that point from what Park tools say.
That's one of the images they show as the chain being too short, looks very like yours at the minute. Adding in a single inner and outter would be fine in my eyes.
About the clamping the cable wrong, my first thought that it was the connecting pin protruding slightly, but it turned out to be the cassette in the end.
Sorry I assumed you were using an Ultegra chain also.
Your derailleur looks a littttttle stretched out to me. The chain should never be almost straight at that point from what Park tools say.
That's one of the images they show as the chain being too short, looks very like yours at the minute. Adding in a single inner and outter would be fine in my eyes.
About the clamping the cable wrong, my first thought that it was the connecting pin protruding slightly, but it turned out to be the cassette in the end.