I think the marble naysayers have jumped on the bandwagon without really living with the stone. I have statuary in my bathrooms and love it. Most stains can be removed with a simple baking soda and water poultice. Acid etching is harder to deal with since it removes the polished surface, but its part of having a living stone in your home. If it becomes too bad, you can have it repolished. With a darker stone, you won't have as many issues as a white marble. In order to really know if you can live with it, I suggest you get a small sample of the stone and do some tests. Here is an example. http://www.dohiy.com/2013/04/21/marble-countertops-the-post-acid-test/ Please note that she used bleach and oxyclean to clean the stone after her test. Stay away from both since they can etch the stone just as much as an acidic food. Instead, clean with a ph neutral cleaner like isopropyl alcohol (rubbing alcohol), and for heavy stains, the baking soda poultice mentioned above. You have to remember that marble has been used for centuries as flooring, table tops, countertops, etc. throughout the world and most of these installations are still here and aren't stained and etched to the point that it has been ripped out and replaced. Just think about all of he luxury hotels in Europe and how many times they have been exposed to Hangover type guests without any damage.

there is no perfect dimensions for an island. Try to organce space subdividing into smaller cabinets of 60x60 cms which is the max space for a structural division and works for seating area as well

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?

Totally doable as long as the island is not too bulky. And of course if the circulation space around the island is at least 3'-0" wide. You don't need too much space to move around in a kitchen because you should be able to pick up a hot dish and put it down on another surface without having to move too much. 12'x14' is a large size and a work island would possibly make the space more practical to use. In the pictures attached, the work island is only 2' wide but 4' feet long