Greetings,
I would like to take on your project.
your proposal of white listing ALL of google CDN ip addresses on your site might not be possible,given how CDN works. There are lots of ip addresses, and you might not have the complete list,since google doesn't provide this.
I am however ready to listen to your problem, and find a solution.
If interested, kindly contact me via chat so we work on this.
Looking forward to hearing from you.