Godzilla as Hiroshima is such a well-worn trope at this point that there's apparently a documentary. I haven't seen it. It's been argued that anime characters tend to have big round eyes because of a subconscious obsession with the conquering culture of Westerners but most students of anime will point out that they're cartoons and that there's no more reason to assume they're Western than there is to assume they're Japanese. Here's a starting point on Superman, the fascist. To be fair, this is 20-odd years after Frank Miller basically made the argument that Superman was a fascist and Batman was a libertarian/anarchist. 
Wow, really really insightful read on Godzilla. I feel terrible for enjoying the most recent Godzilla remake. This reminds me of why a lot of the original "monsters" were created in the first place like the werewolf was created out of the fear of a serial killer, or something to that nature. The Superhero thing is definitely something I've seen a lot of. It actually ran rampant in the most recent Batman v Superman to the point that I could barely finish the movie at all.