I know zero about animation but from the questions you're asking, it sounds like you're tackling a highly ambitious project with perhaps too little experience - no offense and perhaps I'm wrong. I know its tempting when you have a grand vision to try to do it all, but maybe starting out with a smaller story, maybe a backstory for one character or whatever might be more practical, with a better chance of a satisfying result. That pretty much applies to anything in life :-)

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken