At least initially, presenting the factors that lead one to one's conclusion before presenting one's conclusion projects a lower level of confidence in one's conclusion than presenting one's conclusions before presenting the factors that lead one to these conclusions. Altering one's order of presentation in this fashion is not equivalent to lying and moreover is actually conducive to rational discourse.

Stating one's absurd beliefs is not the problem. The problem is expecting those statements to have arguing power (and you don't appear to appreciate this principle). Arguments should always be statements with which people having the discussion already agree, so that persuasion occurs by building a proof of the target belief in opponent's mind from and by the beliefs already present. Not every statement one believes in is a valid argument, not even close. I'd even go as far as to claim that what you believe doesn't matter at all, only what the opponent believes does. Some of the opponent's beliefs might be about your beliefs, but that's a second-order effect of no fundamental importance.

At each point there are bound to be statements which are evaluated differently by different people, it's a simple fact to accept. Irrationality is signaled by inability to follow a rational argument, not by having a property of holding incorrect beliefs. Where one was expected to have been exposed to such arguments, and hasn't changed their mind, this is informative, but not before the first argument is presented.