We tiled down behind the range, lower than the recommended 6" below the range. No fire code issues there. Also, although the trim is sold as "island" trim, it is perfectly safe to use it against a wall (according to Wolf, and our appliance store--we did not order the trim against any objections for our intended use). It was only when we had the burner issues that some of the svce techs pointed to the trim as a contributor to this problem. Not all techs agreed with that "theory" though, and there were also a number of people with taller trims on their Wolf AG's who were experiencing the same problem as well. I am sure having the lower trim does contribute to the backsplash discoloration/grime. No question about that. However, we 1) much prefer the look of more tile/less range trim, and 2) like having full use of/access to our rear burners. Higher trim can, and often does permanently discolor. Sticking a piece of foil behind the trim when roasting or using high heat for extended periods is simple enough to do, and I can toss it out when done vs scrubbing the backsplash each time I cook certain foods.

One of the things I decided to do when we redid our kitchen is to be diligent about wiping down the area behind the sink. There is just no way to avoid water getting on that area. So, I automatically wipe it each time I use the sink. My kitchen is going on four years and I don't have staining. Really, just takes two seconds out of my life.

I used 511 porous plus (not impregnator) on our limestone floors, and will be using it on our marble countertops. From the FAQ on the website, it seemed like PP was better to resist oil stains, which I felt was important for kitchen counters. We sealed all the floor tiles with 2 coats before laying and grouting them. Then we will do another coat to protect the grout. Personally I would play it safe and seal the tiles before they get grouted, but really I don't know what would happen (if anything) if you didn't.

I like the white subway tile rather than the gray. I'd do a contrasting grout (especially if you cook a lot; white grout is a pain to clean). Then if you wanted your walls to be something other than white, there isn't a competing color palate. We did something vaguely similar in my kitchen. When we bought it, there were white cabinets, marble counters, kind of creamish gray walls and no back splash. It's amazing what a simple back splash and a little paint can do...