What is the surface like? Some tiles are too slippery for showers, and some ceramic tiles are too absorbent for wet areas. You should be able to find the specs from the source.

The general rule of thumb is ceramic walls and porcelain floors. Although ceramic tile is acceptable on a bathroom floor, porcelain tile is more dense and impervious. I suggest you ask the retailer or individual you're buying from the PEI Class Rating. Tile is normally a lifetime floor once installed, but I have seen worst case scenarios due to excessive foot traffic. Since this is a shower floor you should not have that problem, but it's good to be informed.

No the general rule is, ceramic tile throughout home except for any wet areas (showers) or outside use. Porcelain can be used anywhere! The pei rating is the strength of the tile, 1 being the lowest and 4-5 being rated for commercial use. I only deal with commercial rated tiles for home use.
Dal Tile has a product that looks very similar to the product you are using but their product is porcelain. Ceramic acts like a sponge when introduced to a wet area and will cause problems down the road. A porcelain product or natural stone would be best for your wet floor in the shower.