I want to keep my dough where one of it's ingredients is powdered skim milk, as long as I could out side fridge before the milk goes off. How many hours are possible? Also if the dough is put in fridge will that stop it from rising? Thanks
The ingredients (milk) don't matter. You are not storing milk, you are storing dough. So it behaves like dough, not like milk.
Dough is full of yeast (obviously). It fills the ecological niche which would be taken up by pathogenic bacteria in other foods. So, no bacteria can take residence there, regardless of the presence of milk. Treat it like any other dough - you can keep it on the counter as long as you like.
And in general, the shelf life of food is not calculated by the shelf life of its most perishable ingredient.