in some cakes you do need to use milk
yes
It depends on the type fo cheese, and what milk it was made from. A whole milk cheese will have more fat in it, but a reduced-fat cheese (made with 2% or skim milk) will have less fat in it.
Whole milk has more milk fat in than Low Fat milk. By comparison whole milk has 3.4 - 3.6% milk fat where Low Fat milk has 1.5 - 2.0% milk fat.
51% is in whole milk
Yes, it will change what ever you are cooking. Another option is to use a little non-fat powdered milk mixed with the water, it cuts down on the fat instead of using whole milk.
Skim Milk is better because whole milk has the fat in it. Skim Milk has no fat because they took it out.
it depends, how big is the cake?
Yes you can, the fat content in milk .04 - 3.5% has little effect on a recipe. One cup of whole milk contains 9 grams or a little less than 2 tsp of fat. 2% milk has about 1 tsp of fat.
Whole milk is NOT usually cheaper than skim milk. Skim milk is usually cheaper, because the milkfat that is "skimmed" of the milk has value and can be sold on its own.
Milk is not a fat. There is lot of fat in whole milk. This fat being animal fat, it is saturated fat. Saturated fat is not good for your health.
Whole milk is milk that contains at least four percent milk fat. It differs from low-fat and skim milk and has a creamier taste and texture.
5.15
Whole milk has a lower fat content than light cream. Whole milk has about 3.6 - 4% fat while light cream has above 12% fat.