normally yes, but in cooking u should probably use real milk...im not a hugely reliable source though... :) ... Yes, powdered milk is a very good substitute for "real" milk. Reconstitute the powdered...
Soy milk can be used instead of milk when baking, but one has to make some adjustments. Regular milk has natural salt; not plain soy milk : minor adjustments may be needed. Then, there are flavored...
No, coconut milk and evaporated milk have very different consistencies. Evaporated milk is milk that has about 60% of the water removed which is why it is so thick. Coconut milk is a much more watery...