I forgot to add something to my wish item #2 above.. There may be times when suppression of syslog alerts is not desired, even if the device is unmanaged. So, this is how I envision it working....
When a node (or a group of nodes) is selected to be unmanaged, a prompt will ask the person if the syslog alerts should be suppressed as well. The suppress syslog alerts option will be checked by default. So, the person will need to un-check the box if he/she does not want to suppress the syslog alerts. This will make everyone happy, those that want/need the syslog alerts and those who don't.
NPM developers... keep up the good work.