The only trouble I have with the zentradi is that they would normaly cause multiple problems:
Why can they exist in the first place? the human body can't be scaled that way, many unsolvable problems arise when you try to do so. Even some tricks from other know species can't apply... But who cares this is an anime.
Huge body means huge needs. Water, food, cloth etc... the toll would be quite high for a closed system. But you could always say that the system was calculated with that in mind. Yet, micronised zentradi should be the norm because it's always easier to scale such a system with reduced needs.
Isn't it dangerous to live around people that can crush you if they are careless, drunk, or just stumble and fall on someone? Because you can tell they weigh a lot from the pounding sounds they make when they walk. They seem to be 10 times taller than humans, that would mean 1,000 times heavier. Scary isn't it? But interresting