A very rough guess - about 4-6 months on the shelf, 9-12 months in the fridge, and about 2 years frozen.
Personally I would refrigerate after opening.
If the tub is too big, then put some in a smaller container for everyday use and freeze the rest?
The "Seven Deadly Sins"
Grains (wheat/rice/oats etc) . . . . . Dairy (milk/yogurt/butter/cheese etc) . . . . . Nightshades (peppers/tomato/eggplant etc)
Tubers (potato/arrowroot etc) . . . Modernly palatable (cashews/olives etc) . . . Refined foods (salt/sugars etc )
Legumes (soy/beans/peas etc)