Yes CDN can help to server the images but the best and latest technology is using service worker .
USing wp rocket will help with some extent as it has page caching , database caching .
as we have in this tip : https://www.youtube.com/watch?v=3IRNZDGBcDQ
This reply has been marked as private.
Yes the Combine JavaScript files! wont work .I would advise you to use servicer worker , you wont need to combine any files then ,
servicer worker is our internal mechanism which caches files in browser makes the page to load superfast .
1 . cant be removed , all necessary scripts are loaded .
2 . this depends on your server ,
3 . same as 1 .
4 . this is from php fetching required data .
.