There's a script that creates perfect circles from edge selections: vimeo.com/65246315 Maybe you can use that to fix distorted edge loops when you need to.
That trailer is a billion times more captivating than the American version. I was already excited to see it, and now I'm just about to run around in circles in excitement.
I'd split he circle of polys on the top of the bun out into a separate island and then straighten out the others. You'll get less distortion and it'll be easier to texture.
Your concept is really nice, and you're off to a good start :) This might help with your perspective and spacing , Ive circled some of the main problems i noticed: