Why is it 'Takemicaduchi' rather than 'Takemikazuchi'? While both can be correct depending on what Romanization system one uses, 'Takemikazuchi' is much more intuitive in terms of pronunciation.
One rule of transcription: Regardless of whatever the rules of Hepburn or Shin Kunrei Shiki or whatever method would dictate, the official transcription takes precedence.
'Takemicaduchi', which is written on the tank's screen, isn't correct by any sort of standard - what sort of romanisation scheme mixes ke and ca?
Cool gadget, Hopkins, but... how could it possibly help you in that situation? Tied to a chair, our villain reveals that he has a hidden spring-loaded knife on his boot's heel, and smirks smugly. Quite the wallbanger.
Such things do exist (although not necessarily spring loaded). The utilization would depend on exactly how he was tied.
What happened in this world to make it that Romans are dark skinned and speak German?
There is a Real World precedence for both, although not at the same time; the Holy Roman Empire was founded during the first millennium of the Common Era, and was Germanic in culture despite of the name. And when the Ottoman Turks conquered Constantinopole at the end of the 15th century, their Sultan who greatly admired the Roman tradition crowned himself the Emperor of Rome. The name and title go around and come around.
Carrying around those heavy packs in episode 5...would definitely cause those girls to develop permanent back pain.
Where would the receding water go?
Historical precedence offers the ice caps as a possible solution; the world could be in the midst of an ice age. Or it could be them.