#1
Zip wallets keep sand, lint and dirt away from your cards, resulting in a very tidy and clean wallet. Your main card goes at the front, and the rest stacked behind.
#2
While we generally discourage coins being kept in your wallet, the Very Small can handle coins reasonably well in the internal pocket.
#3
The Very Small is often used to keep loyalty cards in your bag. This lets you slim down your main wallet for day to day duties.