Replace Silver interconnect cable , please advice

So your source may not be a good match for your system, but don't start buying new gear yet. First try different placement of gear and sofa. Al pointed out possible bass suck-out; can you move the sofa close to the rear wall and toe-in the speakers?
Concerning weak soundstage, you'll never have a wide soundstage with the entire space between the spkrs filled with furniture. You need some air between the spks, maybe switch that IKEA unit to something vertical or shorter and put the amp on the floor (using good anti-vibration feet).
Also experiment with a blanket over the TV; it's causing reflections.

Again, the cheapest tweek is to move the couch back, toe-in the spkrs and have a listen. Unless you already know the Focals are the problem. :)