Skechers Men's Segment - Rilar Oxfords

good day, what do i clean this shoe with?

Are these shoes good for excercise or just for work? The dress code at my work is formal but I have an injured in my feet and need something comfy.

Are the insoles removable?

These appear to have a grey line on the side along the sole. I need all black like i saw this pair in store. Why do these have a grey line?