WHITINMen's Minimalist Trail Running Shoes | Wide Toe Box | Optimal Barefoot-Feel

What exactly is a zero drop running shoe?

I am used to Vibrams, but this year their sizes all run small, so my size 9 foot would be a size 10 shoe. So this is size 8?

I wear a 10.5 men but there's no selection

Is the sole hard enough to trail run? I’m looking for a cheap vibram sole alternative.