more binding (speeds it up to a point)

If there is more substrate, then there are more molecules moving around and therefore more chance of collisions and the substrate binding with the active site. This rule works under any enzyme circumstances unless the question states that there are a limited amout of active sites. If there are 20 active sites and 40 substrates, then at any one time only 20 active sites can be occupied, and 40 substrates will be useless until they collide with a vacant active site.Ideally, there are the same number of substrates as there are active sites. 😆

when [S] > active sites, the enzyme is completely saturated and V = Vmax

More S = more successful collisions.
Successful collisions are those that could bind with enzyme.

depends on whether the enzyme is elastic or not. If the enzyme is inelastic, a rise in substrate concentration won’t have any effect on the flux of the reaction.