Fabric Apps is Microsoft preview technology. The item type, the CLI and the runtime are all still changing, and a template that deploys cleanly this month may need a version bump next month.
Apps install into one tenant. There is no cross-tenant distribution in preview, so you cannot hand this to a client as a hosted product yet. You install it in their tenant, or they install it in theirs.
Light theme only in this version. A dark theme is on the list, not in the box.
The approvals audit trail records who decided what and when. It is not a compliance-grade change-control system.