A VM interface can send packets to the external IP addresses of Google APIs and services using Private Google Access if all these conditions are met:
- The VM interface is connected to a subnet where Private Google Access is enabled.
- The VPC network that contains the subnet meets the network requirements for Google APIs and services.
- The VM interface does not have an external IP address assigned.
- The source IP address of packets sent from the VM matches the VM interface's primary internal IP address or an internal IP address from an alias IP range.
A VM with an external IP address assigned to its network interface doesn't need Private Google Access to connect to Google APIs and services. However, the VPC network must meet the requirements for accessing Google APIs and services.

Anthos :
Anthos unifies the management of infrastructure and applications across on-premises, edge, and in multiple public clouds with a Google Cloud-backed control plane for consistent operation at scale.
- Build, deploy, and optimize apps on GKE and VMs anywhere-simply, flexibly, and securely.
- Consistent development and operations experience for hybrid and multi-cloud environments.
Key features:
1. Enterprise-grade container orchestration and management service
2. Automate policy and security at scale
3. Fully managed service mesh with built-in visibility
4. Modernizing your security for hybrid and multi-cloud deployments

Preemptible instances function like normal instances but have the following limitations:
-> Compute Engine might stop preemptible instances at any time due to system events. The probability that Compute Engine will stop a preemptible instance for a system event is generally low, but might vary from day to day and from zone to zone depending on current conditions.
-> Compute Engine always stops preemptible instances after they run for 24 hours. Certain actions reset this 24-hour counter.
-> Preemptible instances are finite Compute Engine resources, so they might not always be available.
-> Preemptible instances can't live migrate to a regular VM instance, or be set to automatically restart when there is a maintenance event.
-> Due to the above limitations, preemptible instances are not covered by any Service Level Agreement (and, for clarity, are excluded from the Compute Engine SLA).
-> The Google Cloud Free Tier credits for Compute Engine do not apply to preemptible instances.

Enabling Requester Pays is useful, for example, if you have a lot of data you want to make available to users, but you don't want to be charged for their access to that data.
Reference link- https://cloud.google.com/storage/docs/requester-pays

BigQuery is an enterprise data warehouse for large amounts of relational structured data Serverless, highly scalable, and cost-effective multicloud data warehouse designed for business agility.