You would have a legal record of the creation and creation date of your work.
If copyright law did not apply to the internet, it would be nearly impossible to monetize anything on it.
In member countries of the World Trade Organization, copyright protection is automatic; registration is not required.
be sued in court for copyright infringement
Nothing will happen to a person who breaches copyright law unless the holder of the copyright chooses to sue the violator. The lawsuit court settlement will determine the monetary damagesowed to the copyright holder (if any).
You would probably be the owner of the design would probably take you to court where you would either have to buy the copyright or cease its usage and return it to the owner. using copyrighted designs without permission is illegal.
The system would check the dates of posting and note that the claim is fraudulent.
The legislation of whatever jurisdiction you happen to be in.
No, you would patent the wheels on a bus, not copyright.
A corporate entity would not have a copyright date.
In the case of a work-made-for-hire, the copyright would be controlled by the entity that caused the work to be created, rather than the creator. A photographer under contract to a magazine, for example, would not have copyright for those photos.
Generally the writeup of the project would be protected by copyright.
A Copyright would protect an authors idea.