Can't answer the first one, too many ears.
When you spend all 5 activations, contact me for a reset, if not requested too often, you have nothing to worry about.
With proper backup of the activation file, you should not need more than 1 per machine that you own.
VMs are the only pain point, as people don't understand that even cloning the VM randomizes its hardware serial numbers.
So if it must be a VM for testing, just make sure to treat it like a real machine, and use snapshots to make sure you can always come back to the known state.