I've found a couple things help in getting your WLC's managed in NCM.
The first is to set up a separate connection profile that has the "Enable Level" set to "No Enable Login". I personally also use SSH here as "Telnet" on IOS devices seems less reliable to me, not to mention insecure!
The second is in the "Edit Properties" for the node itself, go to the bottom in the "Communication" section where it says "Device Template". Normally you'd leave this set to "Auto Determine", changing it to "Cisco WLC" seems to have helped...
With these two changes I have pretty reliable results. Haven't worked on getting RTCD working on it though!
That being said, having looked at the configs it downloads I'm not too happy with them. I don't believe they could restore a box to working. I'd much rather they get the equivalent from doing the whole "transfer upload mode tftp" and "transfer upload start". Haven't been able to figure out how to integrate that with NCM yet!!