Roca Limestone Effect Ivory Matt Porcelain Wall & Floor Tile

You could but as they wouldn't be secured to a substrate they may be susceptible to damage. They are at their strongest when they are securely affixed to a substrate.

The closet match would be our Rocastone Grey Stone Effect Porcelain Floor Tile SKU: 449935.

If you install onto a concrete base with tile adhesive then you can use a 10mm slab.

Yes, this tile is suitable for a driveway providing it is installed onto a cured concrete base and adhered using an exterior tile adhesive.

We would recommend between 75-100mm.

Either of these grouts would be a good choice Norcros Rock-Tite Brush in Grout 15kg - Steel Grey SKU: 451490 or Ultracolor Manhattan (Light Grey) 110 Flexible Grout 5kg SKU: 6011005A

Being 20mm thick, these tiles can be laid directly on top of grass yes.