sounds exactly like what Gitpod self-hosted is for: https://www.gitpod.io/blog/gitpod-self-hosted-0.4.0/
No.
I think Gitpod Self-Hosted was successfully installed on GCP, AWS, and Azure, and we're working on documenting the process.
It also works with self-managed GitHub and GitLab installations (with Bitbucket coming soon).
No.