actually, to brighten up this dark and small feeling space, i'd look for a creamy base colored stone like khasmir gold or ivory gold, being sure to add an overhang on the island (if you like movement in the stone check out juprana granite) then exchange the pot rack over the island with either a pair of great pendants or a statement chandelier. from my own kitchen remodel experience i'll share you with you this: you'll get a much better price from a granite company then you will from a large home store ;) and be sure to take a cabinet door with you to shop. you can continue the granite onto the wall as a backsplash...they can cut the stone and make it go higher up the wall than the standard 3 inches which can be a great look. but if you really want tile, go for something simple that won't compete with the granite....like a cream colored subway tile. you can apply thim in a running brick pattern or a more modern stacked geometric pattern or even a herringbone. to control staining from food prep, don't use a white grout, use a slightly darker grout color that is inspired from the stone countertop. just remember that using a pattern on the countertop and another pattern on the backsplash can easily become overwhelming and then neither element stands out as the focal point. if you are spending a lot on a granite countertop, do everything you can to make it stand out as the best feature.

Yes if the tiles are not cracked and are in usable condition. You can also choose to leave minimum gap between two tiles.

antislip and easy maintainance tiles for exterior is the key. choose any shade, colour, size. must not have deep textures as that's gonna be tough later in use. do consider slope and drainage appropriately as terrace may lead to water proofing issues in future. make sure skirting is everywhere and corners with top part of the balcony wall is tiled properly. thanks shradha shah beescheese design

glossy finish brass/steel strip or metallic grout will look good .it has various colour options .. but gap if in wet area of bathroom is not a recommendation