Check with Qlik Support immediately.
There are ways to back and restore QlikView's QVPR (repository data) both if they are using XML files or a database.
With regards to the license, once the tasks have been created they will not be removed, even if the QlikView Distribution Service does not work or even it is uninstalled: all the XML files related will persist on the disk.
However, if the customer does not want to use Publisher, those tasks will very likely not be readable by QlikView Server.
The reason why some tasks are not correctly migrated and why you need to contact Qlik Support is because QlikView Publisher creates a new folder structure and stores all tasks in a different way than QlikView Server does (QVS tasks are mainly reload only). QlikView Server and QlikView Distribution Service are two different software components with their own executables and configuration files and folders.
In my experience, unless there are recent changes in latest versions of QV12, you need to recreate the tasks in the QMC if you want a proper, clean installation both if you install Publisher or remove it.
To deactivate the license use the QMC and apply the adequate license, otherwise the service might still run but will not be supported by Qlik.
Even i have to install a QV Server+ publisher in new machine and i want QMC to automatically pick all task from my another existing QV server+Publisher setup.
Please help me understand how can i achieve this?
Will Copying QLIKTECH folder (including all subfolders , Distribution services, Management Service (+QVPR and all other subfolders)) automatically bring same setting (QMC settings and all tasks ) as existing system into new system?