That ruins up the elegance of the silk-faced lapels. And pick stitching is typically done on the edge, not 1/4" in, which is more appropriate on a sports coat. If you want to set yourself apart, get turnback cuffs on the jacket.
I know the traditional sharkskin (pick-and-pick), which is an even twill weave that alternates black (or coloured) and white yarns in both the warp and weft. But what is the shiny sharkskin exactly? Is it the same weave, just in mohair or polyester? I have a traditional sharkskin suit in all wool and it isn't shiny at all.
They are not formal enough with a business suit. They are okay with tweed suits and with sports coats, but I'm I'm going to wear something between my jacket and shirt I prefer a waistcoat. A jumper is too bulky.If your "belly zone" shows below your jacket that's another problem. It means your trousers need a higher rise or your jacket's button stance is too high. Nothing should be showing there.