On Space-Time and the Universe

If all of the electromagnetic radiation we can sense from space using various types of receivers, including the visible spectrum, actually represents views into the universe at different times based on the distance of an object to earth and the speed of light, then all that we know about huge parts of the universe is based on data that is thousands or even hundreds of thousands of years old. If we could see the universe instantaneously or at times near what we are accustomed to with close objects, what would we see? How different would our understanding of the universe be? Considering the magnitude of the distances between celestial bodies like galaxies, what is time when measured using human standards like days and years? For all we know, large portions of the universe will have been destroyed and reborn several times by the time we see the light from such areas. For that mater, if the universe began to end in some distant part relative to us, how long would it be before we were even aware of such?