First, it's to fine-tune how the RP's gonna be played. Either close to the 70s Hanna Barbara TV version of Godzilla, like you mentioned, or like the Godzilla 2nd & 3rd movie series, or similar to Ultra Galaxy, like I mentioned, or some kind of mix, or something else entirely. Here's a list of questions to discuss answers for.
Toony or Realistic?
Communications between kaiju & people?
Other races beside humans, kaiju, & aliens?
Technology?
This list can be modified for more questions.