No. If it is the name of a person, place, or thing it becomes a proper noun. Otherwise it is a common noun and is not put in caps.
No, not unless you are referring to an organization.
Yes I have reason to believe that its capitilized
humming bird does not need to be capitalized.
it does not need to be capitilized.
No, not unless it is a specific college..ie Manchester College, or if it begins the sentence.
No, the word astronaut is not capitalized in that sentence.
No, except at the beginning of a sentence because it is not a proper noun but American should always be capitalized.
No
No.
Judging by your pallor you need to go out and get some sun.
In the warm sun the crops started to sprout.
I need "protection" from the sun so I don't get hot.