Personally, I like kitchens that have a very limited number of finishes - they seem timeless and pulled together. When we did our kitchen several years ago we worked within a very strict palette - we have a slab backsplash with the Quartzite counters and it creates a quiet vibe (plus I think tile dates really fast). If you absolutely love your countertop material and you like the slab look then I would say go for it

Your selections are pretty, but is the backsplash okay to use behind the cooktop and oven or will it scorch or worse ?

I think the Metroquartz would look look great for all your counters along with a simple white tile (or possibly a light grey) backsplash that would compliment it. The Metroquartz is lovely on it's own, I think it would be too much of a good thing to use it as a backsplash as well. Love your floor color too!

You are correct to busy with the dark backsplash. You eye would follow the lineal dark splash. 
I would use the counter top material for backsplashs.  imo.jja

I concur with the idea of simple white backsplash tile (perhaps a high gloss subway tile). The counters would look more special and you’d have freedom to add interest with accessories

Go for it! It will look rich!

https://www.houzz.com/magazine/the-future-of-backsplashes-stsetivw-vs~29887594

Plus, the gray island will keep it from being too “busy”
White backsplash tiles are a snoozfest

It will be beautiful with the Metroquartz counter and backsplash. Go for it!

Too busy, too much movement in that countertop to have it on the walls too. Someone commented that white tile is a snoozefest. I don't agree. In this kitchen it is going to be all about the counters and they certainly are not a snoozefest. Not every inch of a kitchen needs to have a bling moment. Give the eye a place to rest with the backsplash and let the counters steal the show instead of trying to compete with them.

I think it would look nice only if the backsplash and countertop are from the same slab so it matches at the seam.

Really pretty combination of materials!

It seems we all have been bamboozled into believing that we need an elaborate countertop and a fancy backsplash and clever hardware and multi-colored cabinets and trendy flooring, etc, etc, etc...... Aside from the fact that people go into fantastic debt for kitchen renovations, it is so easy to overdesign and overpattern an area that is going to accumulate countertop appliances, decor, dishware, paperwork, and all the other items of daily living. Visual overstimulation adds to stress levels. There is beauty in simplicity. Limit your selections to one or two colors or patterns and create a lovely and subtle backdrop for living.

"Your selections are pretty, but is the backsplash okay to use behind the cooktop and oven or will it scorch or worse ?"

Not if the appliance is installed per the manufacturer's installation instructions.

Kendrah:

The geometry of tile complicates visually. In this case more is less. I agree with la_la girl.

Looking at your saved images in your ideabook you don’t have any showing a slab backsplash. You don’t want to make any decision lightly so please find one here from Houzz that does have a slab backsplash that leans towards the vibe you are striving to achieve. If you post your kitchen drawings that might help. My knee jerk reaction to that specific quartz you like is rather busy for a backsplash but context is everything.

IMO a plastic quartz is never a good idea behind a range no matter what Joseph says in fact IMO quartz is apoor chice for counters too. I do agree less is more in finishes in kitchens but I would do a nice white polished granite for all the counters and a large format glass tile with matching grout for the backspalsh and the tile just a color form the counter

I love the countertop but would choose a plain tiled backsplash instead of that slab. I agree with @Kendrah. A knockout countertop needs simplicity around it to be the star. Your island choice is good and a plain backsplash continues the theme. Lovely choices!

Is it possible to see much larger sample? Choosing based on your small sample is not recommended, especially if doing the backsplash. Below is an example on their website.

Personally, I love the one below with the simple, classic veining if using as backsplash as well. If you use Feather, I’d be tempted to tile.

Love your selections….beautiful! Could you please share the info on the wood flooring?

Croft Oak - Ludin (Neup08)

That pattern is too busy to go vertically IMO, but it will be lovely as counters.

Thanks so much for the flooring info! I am sending you a link you might want to see. I like the look of the countertop material used also as a backsplash. Very clean and sophisticated. Just depends on how much of a backsplash and how busy the pattern. Hope you post your final project. Good luck and have fun!

https://www.instagram.com/p/CVsdTkpLh8h/

Strongly recommend seeing slab of quartz in person. I find this pattern for island too busy. Check it out at slab location. If you still like it, go plain everywhere else. I also think this quartz can look different in different lighting Congress.

“Conditions” not congress. What has happened to spell check???