Many people have asked him various questions but his responses are incoherent.
Taking this statement at face value (as I have no opinion myself), anyone who is reported as being incoherent, yet planning a "big trip" must take a step back and evaluate their situation. I once interceded when I was aware a friend was going flying, and he was at present in an incoherent rage about something I've long since forgotten. I told him he was medically unfit to fly at the moment. He stopped, paused, and calmly said to me that I was right, and he would calm down before he flew. Everything worked out fine.
Judging entirely from the outside looking in, Mr. Kirk seems to me to be a person who's mind may not be up to the task of a "big trip" for a little while. Ignoring warning signs is irresponsible.
Jetblu, I'll have a look around here for extra keyboards, I have some somewhere - though I don't really understand....