I like this tile as well. Very sleek and mod looking. I would consider running it vertically instead of the picture horizontal pattern. It might give the illusion of more height in the shower surround. The color is great. If you are worried about it being "too much," you could always see if they have the same tile in a different shade and mix the two or doing one wall in a contrasting (lighter) color. I personally like it as long as you have good lighting.

A houzz contributor, not too long ago, had made a wine rack out of 4'x4' wooden pallets, that are used in the US to move a load of goods with a fork-lift truck. Perhaps they have them in your country. He cut them in half so they were only two feet deep and stacked them up to high counter height. The wood would be a nice contrast with your concrete, might add a little warmth to the space. cascio.offsite@gmail.com

Usually when you get side panels you automatically have space on the sides. If you have a full depth cabinet on the top, you automatically have space at the top and in most cases you will have leave at least 1 inch of extra room for the back of the refrigerator, so there is always air circulation since everything is enclosed. In the 70's they use to make a small recessed space behind like Fred said, today you don't have to do that, most Ref have flat backs, recessed wiring, not to mention the supply for ice-maker also comes in a flush mounting kits for the wall... so pretty much everything is recessed and only space you need is for air circulation and 1" is more then enough. In addition, if you make recessed area now and you push ref to far you will never get your doors open so doing all that is a waste of time, in addition most manufacturers starting to make 30" side panels.

Your choices don't flow well to me. The flooring in your photo is pretty (very dark...are you okay with it showing every footprint, smudge, and dust bunny? If so, that's fine). From all of your options there I would do white cabinets with the Himalaya White granite. But you said ignore the granite. :) I would go for the gray cabinets with white quartz everywhere in that case, but personally I'd worry about gray cabinets being very dated in a few years. Is there another quartz option that you could pair with the white cabinets that is light in color and maybe has some movement, like LG Bianco Drift?