But for academic purposes---if such a god existed--all powerful, all loving, forgiving, merciful--I think he would find a more appropriate "punishment" than eternal suffering. He could do anything- no limits.
All things are "suffering" unless God intervenes. This is the second law of thermal dynamics. All things are in a state of decay. However, God and ONLY God, being the author and source of LIFE, can intervene. Suffering is the default reality due to a lack of intervention by God. The confessions of our mouth is what moves the hand of God in our destiny.
For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. Rom.10:10
God gives both the believer and the unbeliever what they ask for. What could possibly be more fair than that?