The answer to your first question is, the following are some major properties which we have to be verified before shipment,
1. Specific gravity 2. Reid Vapour pressure 3. Octane no. (RON) 4. Color 5. Distillation 6. Total Sulfur 7. COpper corrosion test.
For gasoline specifications please study this document
https://www.acea.be/uploads/publications/WWFC_19_gasoline_diesel.pdf
You can also study these individual properties on the internet.