Hi again.
Just wondering whether CDN can be cached or something like that, so if new request doesn’t grab any new content, it’s not considered as a request and as a result is free 
All requests are counted, regardless of new translations. Come on, price is 3$ for any additional 1 million request man, if you have less then 1 m/month you pay nothing for it:)
This technology works cool out of the box, it’s awesome. Still, I’ve seen somewhere in the project where I’m volunteering, they somehow decreased the requests to 1 per hour or so, I guess you can do same thing from you side (should be more info in google, don’t know about your service and server configuration)