The fairness point was a general one rather than a direct reference to anything you said, and the Scriptural basis for eternal punishment has yet to be systematically presented, as well as a rebuttal of your specific arguments.
As for the meaning of death & perish, etc., in the light of Biblical teaching about spiritual death, for example, that amounts to a somewhat facile argument, and I'm pretty sure you know it. When God warned Adam that he would surely die on the day he ate of the forbidden fruit, did he drop down dead on the spot? If you are gonna maintain such a wooden meaning for the word 'death' in Scripture, then you must call God a liar.
That death does not always mean death in the way it is commonly understood by a materialistic world view, nevermind annihilation, is easily demonstrated. So it is with the other words. Their meaning is determined by their Scriptural usage, not by what we want them to mean.