Yes. Apple's not going to come after you for running too many VMs on your personal machine, but if you're running a commercial enterprise involving macOS VMs they do care.
Yes. And the license only allows you to run macOS guests on macOS hosts. So using esxi means you don’t have any license for whatever macOS guests you run.
You are confusing macos guests on KVM (Linux) and macos guests on ESXi which is a real enterprise product, and officially enables you to run as many macos vms as your hardware supports.
