Do you notice the defects located for example near the mixer faucet? I don't know how to solve them, any suggestion?

Yes, I notice. I don't exactly know how to eliminate such annoying artefact completely. I see they typically occur when we render in silky mode of shininessShader.

If you want to render in Silky mode, maybe you can try reducing the shininess of the texture for the object (faucet). I also find that rendering at higher resolution helps. If you have the time and patience, you can try rendering at 3000-5000dpi. It may take 6-7 hours but you can let the computer do the job while you sleep.

Can you tell me Where I can find the light panel created by Enko Nyito?

I don't recall which page or which forum thread I got it from, but it is somewhere in this site. Perhaps someone can help point out the exact location?