Why do people usually only have one front aerospoke (Other then for fashion cause I know thats a big factor in all this)? Why not have two? I heard you cant get the back hub set up fix/fix. That the reason?

Aerospokes are supposed to be used on the track right?
What about deep V style rims? What is the purpose of the deep rim other then possibly shortening spoke length? More aerodynamics for the street? Seems like the deep rim would catch more side winds.

And other then lets say the mavic io what is a good track wheel?