Slalom fin
 

I started to race in slalom competition. Since I`m studying technical engineering i have basic knowledge in fluid dynamics and really would like to understand more about how my fins work… can somebody answer the following questions:

-What is the matter about Twist and Flex?
-What inflouence does the leading edge radius have?
-where shoulde the thickest point of the fin be (% of cord length) and how thick in % should it aproximatly be?
-at what angle of attack does a slalom fin work?
-how much lift does a fin have to produce to counterbalance the forces from the rig?
-does the tip vortex fenomen has an inflouence, if yes, what fin tip shape is best to avoid it?
-what profiles are the most used in fin design, is it NACA? Why not eppler or special hydrofoil profiles?

Thanks!
stefan