I don't see the harm. You might come off as a nutter, but who cares, you're probably never going to see that person again. If looking crazy is your concern then your absolute safest bet at sharing your thoughts with a stranger comes in the form of counselors, psychologists, priests, (or their equivalent) and psychiatrists. You can gab all you want and not have to worry about what they think of you, they're trained to listen without judgment. Granted they may cost a little (or a lot) of money to enlist their services but none of your information will be shared.
If your intention is to make a friend, I would say to just strike up a conversation with someone. Leave personal stuff out unless the two of you are comfortable enough to go down that road.