Sounds like you have a slow connection. 1080p use bandwidth.
-Recording and viewing are separate processes and configured in settings. Maybe you mean view the recording in less quality. Resolution cannot be changed and the server adopts to available bandwidth.
-NCS do not change resolutions. Usually, new IP cameras deliver several streams simultaneously so you can config one stream for cam1 and a second stream for cam2.
-You can limit the FPS for the client in Settings.
-You can also limit the bandwidth in the user account so you can use different accounts depending on the application.