As for skateboard sizes that's really all personal preferance and what style you plan on skating. For street, park and pool you're going to use the most common sizes of skateboard that range from 7.5 wide to 8.0 wide. Usally people stay in the narrow range like 7.5, 7.675, or 7.75.
The smallest skateboard size is about 7 inches in width by about 24 inches in length. The skateboard is legal size for contests and events.
8.0
Doesn't matter
it might depend on the size of the skateboard but mine are 2 inches exactly
no
8.000
7.75 by 31
yes you can
7.8
it's lenghth and width
7.75x31.0
it depends on what size your feet are