How to foil are plenty, on Duotone or Fanatic YouTube channels. How to use the shims is fairly specific per board, foil and sail size. Our foils are designed to be used without them, for Fanatic boards/most are actually fine without.
Re sails - the whole idea of foiling is to use smaller sails, so you can normally drop 1-2sqm of sail size when using a foil vs fin?