There should be a difference between people showing bravery in the battle against Overlord and people taunting Overlord. Definitely accept duels, it get's rid of the crazies and allows those who want to role-play an honorable death dueling Overlord that opportunity (everyone should understand that it is suicide).
Anyone taunting you in prison can be assumed to be crazy and therefore putting them out of their misery is the right thing to do.
As for consequences in this invasion, we have already lost half the continent to the blight. Most capitals have been razed. I would say there is a very real understanding of consequences right now.
I am surprised to hear you are not enjoying the invasion, were you not considering starting one on Dwilight as well? I am confused why you would consider starting one elsewhere if the one going on in Belluaterra is not fun for you.
(By the way, I DO understand how statistics work. If what I wrote up on earlier posts does not make sense to you and you care, I can explain it in a personal message)
Why did you think Tom was considering invading Dwilight?