wear it with a black waistcoat, and add some cool badges!!!!!!!!
Jeans and a red cap.
Yes you can.
Normally the vest looks better with a colour coordinated long sleeve shirt. But, if its really warm out a short sleeve shirt will do. Its all in your opinion.
depends on the shirt and tie. but make it a thin tie!
Because he wears them with black sexy leather jeans and silver belts, and he feels more confident and assertive.