Yes, the PTZ Presets are stored either in the server or in the camera. You can see which scheme is used in this way. In the Management Client pick the camera, in the camera properties pick the Presets tab, on the presets tab find the option “Use presets from device”. If this is set the presets are stored in the camera, if this option is not set the presets are stored in the server.
Most cameras will have both possibilities but some will only support one of the two options.
No.
If the Management Server does not run you cannot login.
If already logged in and the Management Server stops you cannot change view as that would require checking whether you as user has the rights to see the cameras in the new view.
If logged in and not changing view and the Management Server stops you can continue to see the camera footage until your token runs out. Please see this knowledge base article for further information on this scenario:
The Smart Client AddUser plug-in sample uses Configuration API methods. It does something completely different in adding basic users, but it shows how you can use Configuration API from a Smart Client plug-in.
Are you aware that there is the functionality in the Smart Client to define presets? I mention this so that you can evaluate that you do not develop what the Smart Client already has..
See the PTZandPresets sample. While creating PTZ Presets does not work for all products using this sample, (as documetated in the sample,) the use of PTZ preset does.