No. 2 percent milk is much too thin and lacks the fat and consistency needed to substitute for sour cream in any recipe. Low-Fat Yogurt would be a better substitute for sour cream.
absolutely, have done it for years
Wouldn't recommend it. It'll add too much moisture to the recipe.
cream cheese
no you cant
Depends on the recipe.
baking pouder
You can substitute 1 cup Mascarpone cheese with 1 cup cream cheese beaten with 1/4 cup heavy whipping cream.
Depending on the recipe, cool whip should in most cases be interchangeable with whipping cream as a lower calorie substitute. Cool whip is an imitation of whipped cream, called "whipped topping" by its manufacturers.
try cream of buckwheat, or cream of rice. or grits. i would try the rice myself.
Try an equal amount of balsamic vinegar.
Baking powder is a 1:3 ratio of baking soda to cream of tartar. You cannot just substitute cream of tartar for baking powder - you also need the baking soda.
Probably, but canned cream is sometimes aerated; if this is the case, you need to whip the heavy cream before using it as a substitute.
If you do not have cream of tartar, baking powder will work just as well, or better. If the recipe calls for both cream of tartar and baking soda, leave out the soda if you use baking powder - it already has soda in it.