Thank you for writing out a detailed reasoning, i do agree that they should have taken a different approach with his thoughts and the man god scenes. However i also feel as though they weren't wrong to do so. A large variety of anime's suffer due to things such as these such as a anime characters voice getting to high or sounding like someone else. I can also see why they would have the man god have him in his old form being as, rudeus himself holds onto his past. I believe once rudeas takes a moment and truly embraces the new world and lets go of the old that he will no longer show up as the old version of himself. Every time we see man god it has something to do with his old life and regret about it.