If you are basing your conclusions about 'time travel' or the legitimacy of Titor on the face value of the posts, then yes, it is nonsense.
Well, I really have no conclusions about time travel. As yet, I see no evidence to suggest that it has been achieved. However, when we start mixing one theory on top of another on top of another, time, dimension, plane, gravity, distance, etc., it can be a mine field. Is it possible? With all of these variables, who the heck knows? I could no more claim it is than I could claim it isn't.
As for "Titor" who actually began his hoax on a different board as "timetravellr" I have brought to attention a few things that have been conveniently lost over the years. Face value is all that we have and it is, without the shadow of a doubt, NONSENSE.