Yes. We refer to all those who have entered heaven, including all angels, as saints, even if they have not been officially recognized as such by the Church. However, those who entered heaven in the days of the Old Testament are usually not given that title.
Heaven for Everyone was created in 1987.
A saint becomes a saint the instant they enter heaven. However, before the Catholic Church can declare them as a saint in heaven they carry out a lengthy investigation to assure that the person is, indeed, in heaven. This is called the canonization process,
There may be a St. Amber in Heaven however, there is no recognized saint by that name.
There is no specific saint known for waiting at the door of heaven. In Christian tradition, Saint Peter is often depicted as the gatekeeper of heaven, with the keys to the kingdom.
St. Michael is an angel in Heaven, he is a saint.
Not exactly. The Church recognizes people as Saints, but what makes them Saints is their own holiness and devotion to God.
Saint Peter is fine and enjoying his life in heaven.
The definition of saint in the Catholic Church is someone who is heaven. Thus to say that someone is a saint is to say that they are in heaven, so the answer to your question is yes, it is a tautology.
I do not understand your question. If Francis Xavier is a saint, that means he is dead and in Heaven. He is doing whatever saints do in Heaven.
We must assume that Saint Nicholas of Myra is currently in Heaven.
Saint David of Wales is living in heaven.
To the best of our knowledge, she is in Heaven. That's why we call her a saint.