what effect does camber and toe have on rear wheels?

doing independant rear suspension for motorsport use on fiesta's for my final year project in uni and would like to be able to incorperate some sort of adjustment into the designs.

if i can use 2 points to adjust camber then i can also adjust the toe by using the same points in theory with careful design and thought.

just wandering if there is any use in working it into the final model.