Hi,
I just deployed a 6.1.2 Appliance on friday and the maintenance service was indeed disabled after the initial start.
Don't know why yours isn't, maybe it's related to the infrastructure size, as yours is a lab environment?
Your Appliance will work finde though. when you take a look at the config in the vSphere client you see your backup and your maintenance window, so backups will only be done after the maintenance window is over.
Tim