Explanation
Oracle DataSafe is a unified control center for your Oracle databases which helps you understand the sensitivity of your data, evaluate risks to data, mask sensitive data, implement and monitor security controls, assess user security, monitor user activity, and address data security compliance requirements.
Whether you're using an Autonomous Database or an Oracle DB system, Oracle Data Safe delivers essential data security capabilities as a service on Oracle Cloud Infrastructure.

Explanation
You cando Costs Analysis in OCI and you can group and filter the cost by Tags or compartments To filter costs by dates To filter costs by tags To filter costs by compartments To remove a compartment or tag filter

Explanation
Budgets can be used to set thresholds for your Oracle Cloud Infrastructure spending. You can set alerts on your budget to let you know when you might exceed your budget, and you can viewall of your budgets and spending from one single place in the Oracle Cloud Infrastructure console.

you better understanding please see the below image of Pricing model.

Correct. Autonomous Databases can be deployed in Dedicated or Shared Exadata Infrastructure.