Yes, applesauce is a healthy substitute for oil whenever you are baking. Just be sure to use an unsweetened applesauce.
You can use condensed milk in a fudge recipe. You will have to reduce the sugar in the recipe to account for the sugar in the condensed milk. Some fudge recipes call for condensed milk.
It depends on the recipe. For some things, it will work, for others, it will ruin everything.
Depending on your recipe: You can replace eggs in the recipe with this formula (per egg): 1/4 cup applesauce or 1/2 banana 1 tsp. baking powder If your recipe calls for milk you can always use water, juice or rice milk. If your recipe calls for butter you can use margarine or shortening.
It shouldn't cause any problems. I have substituted soy milk for regular milk in many recipes without any problems. You usually can't even taste the difference.
no
Heavy cream could be used for milk in cornbread, but the baked cornbread might be heavy and too dense, because of the high fat content of heavy cream. It would be better to thin the heavy cream with water to bring it closer to the consistency of milk before using it in cornbread.
I just had a recipe that I substituted half and half for milk (because I ran out of milk) and I used the same exact that was called for regular milk and my recipe came out perfect. I'm sure if you are making a custard, cream type dessert you will probably be able to tell the difference, but I made apple cinnamon bread and it was fine.
chocolate milk
Yes, you can. However, it will make the dish very rich, and you may want to change it a bit. To have a more 'normal' cornbread, try adding 2/3 half and half and 1/3 water (equalling the same amount of milk the recipe asks for.) If you think it is too watery or too rich, you can change the proportion appropiately.
No. Well, it's not like it'll make the finished meal explode or anything, but the result will be a lot different than if you've used milk.
the process or recipe of making evaporated milk from coconut milk
It depends very much on the recipe in which the substitution is made. Buttermilk has a different acidity than whole milk, as well as less fat. Additional baking soda will need to be added and perhaps a bit of oil or butter, if buttermilk is substituted for whole milk.