Correct. Oracle Cloud Infrastructure Bastion provides restricted and time-limited access to target resources that don't have public endpoints.

Explanation
In OCI a budget can be used to set soft limits on your Oracle CloudInfrastructure spending. You can set alerts on your budget to let you know when you might exceed your budget, and you can view all of your budgets and spending from one single place in the Oracle Cloud Infrastructure console.
Budgets are set on
Cost-tracking tags
Compartments (including the root compartment)

Correct. Object Storage offers multiple management interfaces that let you easily manage storage at scale.

Correct. User access and permissions are managed by the customers.