We have the black mirror splashback. We love it and it soooo easy to clean

Rather than removing the edging, I would add to its width and this wil make the cabinetry look custom and paint it white. I would also keep the corner shelving and replace your accessories - one item/shelf and related to each other. You could add a great fixture instead of the pot light, change the faucet and hardware. Suggest carrarra marble backsplash (don't put the rack back up behind stove) and there are so many pattern choices. It's also interesting how they have laid the tile in the last picture, which I think would work really well with your set up and will save a bit of money on marble. A dark quartz or granite would be complimentary and warm up all of the white. [houzz=]; [houzz=https://www.houzz.com/photos/6-via-aragon-san-antonio-parade-of-homes-contemporary-kitchen-austin-phvw-vp~1042542];[[houzz=]

Not keen on tiles ... prefer a smooth surface with no grout lines to try and keep clean

There are specialist benchtop repair companies that do this type of work. Ask for a quote. These two have been recommended in various online forums by people who use them, but I have not personal experience with them. http://www.toprepairs.nz/ http://www.benchdoctors.co.nz/