Is it possible to access S3 objects from the Internet?
Yes, but it has to pass through EC2.
Yes, it is possible if proper public readable accesses and ACLs are set.
No, there is no way to access any S3 objects from the Internet.
No, only a general overview of S3 objects can be read from the Internet.
Explanations:
S3 objects can be accessed directly from the internet without needing to pass through EC2, provided the correct permissions are set.
S3 objects can be accessed from the internet if proper public-read permissions and ACLs (Access Control Lists) are configured to allow access.
S3 objects can be accessed from the internet if the proper permissions are configured. There is no restriction preventing this.
It is possible to access full S3 objects, not just an overview, if proper permissions are set.