Time Travel Stories: Echoes

As I mentioned in an earlier entry, in the process of preparing for my next novel, the time travel story Golden Girl, I have been digging into my archives, unearthing a few time travel short stories for your reading enjoyment. Here is the first one, a short, compact tale titled Echoes. It is only 1350 words long, so it should be a quick read. I was inspired to write it by the 1975 Roger Zelazny story, "The Game of Blood and Dust", which is as compact a time travel story as you're likely to get.

So, click the Echoes link, read the story, then come back here to answer the following questions:

1. Does this story give a satisfactory explanation why with the entire range of future history and advancement yet to come, we don't see any evidence of future time travel visitors having come to visit us?
2. How many of the mentioned characters and events survive in our historical records and are there any unexplained gaps that might suggest tampering?
3. If you discovered evidence of time singularities, what would you do?