rough finish on concrete is called a broom finish. they take a broom and when its almost set up just push or pull it across the top, it leaves texture. the more pressure you put on the broom, or the wetter the concrete the rougher it will be.
salt will damage concrete. salt will eat away at steel. salt destroys everything over time. some concrete is better quality than others. some areas use more salt, more often. but regardless of quality, given enough time, the salt will hurt the concrete
salt on roads cause more damge than anything else.
we use borium on our horses shoes for trail riding. it helps make the shoe last, and it also keeps them from slipping on the oaccasions we hit the asphalt. we use it on all four but you can get away with it on just two. you may want to consider this option.