I am not familiar with either, but I have never had a problem when asking for something to be left off of a dish at WDW. I would just ask your waiter before you make your final decision...WDW waiters and chefs usually try to please everyone from my experience. Have fun!
Do you mean Le Cellier? LC has a salad with edamame and spicy slaw, but I don't see that on San Angel's menu. Edamame are soybeans; they've got a slightly nutty taste with a texture similar to lima/butter beans. No spice at all. As far as the spicy slaw, you can always ask for it on the side to try it and see how it is.