ashkenaz concerns

Question

I am concerned about the "nuts" in some of the Baskin & Robbins ice creams that are on the list. If ashkenaz cannot eat peanut on the holiday, are these ice creams made with a different kind of nut? There is one called Reeses peanutbutter and another called baseball nut. Gatorade is another concern but I am assuming it is "kosher by ingredient".Is Clear Choice flavored water K for P? Is only the tuna in water K for P for ashkenaz? Is it necessary to purchase fish in a kosher market year round? Thanks for your advice-jeanne