Hi Yasser
Once the form has been submitted, the process has started - there is no way to "unstart" it.
However, you can terminate the processes, which will basically stop the process from continuing, and remove any existing tasks in anyone's task list. You can terminate a process via the adminui, via the Workflow api, or using Avoka's "Process State Changer" qpac (see
http://www.avoka.com/avoka/qpac_library.shtml). You can also suspend a process, which allows you to resume it later if you want to.
At the moment, in the adminui, access is global. In other words, if you give a user administrative access, then they can see and administer ALL process types. I do know that a feature request has been logged to provide access control by process type, but I'm not aware of the status of this feature request. I suggest that you log this as a feature request with Adobe support.
An alternative is that you could build your own custom administrative web application, where you can control exactly what people are allowed to do with what processes. We would also be happy to talk to you about building something like this on your behalf. If you're interested, contact me on htreisman "at" avoka.com.
Hope this helps.
Regards,
Howard